Dr. Masiakos is a pediatric and neonatal general surgeon who is an internationally recognized pediatric trauma surgeon and injury prevention specialist. He is a current member of the American College of Surgeons Committee on Trauma.


Pediatric Surgery


Centers & Specialties

MassGeneral Hospital for Children

Trauma Center

Clinical Interests
  • General pediatric surgery
  • Inguino-scrotal pathology: undescended testicles, hernia, hydrocele, varicocele, testicular torsion
  • Minimally invasive pediatric surgery
  • Chest Wall Deformities (Pectus excavatum & Pectus Carinatum)
  • Pediatric thoracic surgery
  • Esophageal anomalies
  • Trauma and injury prevention
  • Thyroid surgery
  • Pilonidal disease
  • Pediatric Neoplasms
  • Inflamatory Bowel Disease
Medical Education
  • MD, Boston University School of Medicine
  • Residency, Boston Medical Center
  • Fellowship, Toronto Hospital for Sick Children
Board Certifications
  • Surgery
  • Pediatric Surgery
Foreign Languages
  • Greek
  • Boston: Massachusetts General Hospital
  • Newton: Newton-Wellesley Hospital
Existing Patients
Patient Gateway
Insurances Accepted
  • Aetna Health Inc.
  • AllWays Health (NHP) - ACD
  • AllWays Health (NHP) - PBO
  • Beech Street
  • Blue Cross Blue Shield - Blue Care 65
  • Blue Cross Blue Shield - Indemnity
  • Blue Cross Blue Shield - Managed Care
  • Blue Cross Blue Shield - Partners Plus
  • BMC HealthNet Mass Health MCO/ACO
  • Cigna (PAL #'s)
  • Commonwealth Care Alliance
  • Fallon Community HealthCare
  • Great-West Healthcare (formally One Health Plan)
  • Harvard Pilgrim Health Plan - ACD
  • Harvard Pilgrim Health Plan - PBO
  • Health Care Value Management (HCVM)
  • Humana/Choice Care PPO
  • Maine Community Health Options (MCHO)
  • MassHealth
  • Medicare
  • Medicare - ACD
  • OSW - Connecticut
  • OSW - Maine
  • OSW - New Hampshire
  • OSW - Rhode Island
  • OSW - Vermont
  • Private Health Care Systems (PHCS)
  • Senior Whole Health
  • TriCare
  • Tufts Health Plan
  • Unicare
  • United Healthcare (non-HMO) - ACD
  • United Healthcare (non-HMO) - PBO
  • Well Sense Pediatrics

Note: This provider may accept more insurance plans than shown; please call the practice to find out if your plan is accepted.

Patient Age Group
Pediatric and Adult
Provider Gender


Peter T. Masiakos, MS, MD, FACS, FAAP, is a pediatric general and thoracic surgeon at Mass General and Associate Professor at Harvard Medical School. He was trained at the Boston City Hospital and Hospital for Sick Children (Toronto), where he developed a clinical interest in pediatric trauma care and injury prevention. He is the director of the pediatric trauma surgery service at Mass General and has become a vocal injury-prevention advocate. He has broad interest in clinical surgery with a focus on general pediatric surgery (pediatric hernia repair, hydrocele repair, repair of undescended testicles, and umbilical hernia repair), esophageal anomalies, pectus excavatum and pectus carinatum repair, thyroid surgery and pilonidal disease.

Dr. Masiakos has been involved in successfully educating the Massachusetts legislature and the US Congress on the inherent risks that certain products pose to children and has testified both at the Massachusetts State House and at the Consumer Product Safety Commission on the need for new legislation that would prohibit the use of ATVs within specific age groups.  He has aided in the development and passage of several forward-thinking injury prevention laws and continues to work alongside Massachusetts legislators and the Congress on several other comprehensive injury prevention laws including junior-operator laws, safe-driving laws and child-restraint laws.

Research & Publications


View my most recent publications at PubMed

News & Events

  • Addressing an epidemic: MGH launches Center for Gun Violence Prevention

    On June 10, leaders from the hospital and city of Boston launched the MGH Center for Gun Violence Prevention, which seeks to address the public health crisis that causes nearly 40,000 firearm-related deaths each year.

  • Mass General Hospital launches new Center for Gun Violence Prevention

    New center seeks to address the public health crisis that causes nearly 40,000 firearm deaths each year.

  • Mass General Surgeons Named to Boston Magazine's 2019 Top Doctors List

    45 doctors from Massachusetts General Hospital’s Department of Surgery included in Boston magazine's 2019 Top Doctors list.

  • MGH stands against gun violence

    At noon on March 14, the Bulfinch patio and steps were filled with hundreds of MGH staff who joined together calling attention to gun violence as a major public health crisis.

  • Research Roundup

    Research at the MGH is interwoven throughout more than 30 departments, centers and units and is conducted with the support and guidance of the MGH Research Institute. The Research Roundup is a monthly series highlighting studies, news and events.

  • Study finds patients needed fewer opioid tablets than prescribed after hernia surgery

    A study by investigators from Massachusetts General Hospital and Newton-Wellesley Hospital found that patients prescribed opioid medications after inguinal hernia surgery used significantly fewer tablets than prescribed.

  • Masiakos's Lifesaving Efforts Inspire Australian Officials to Change ATV Laws

    In 2006, Peter T. Masiakos, MD, saw firsthand the devastating effects that all-terrain vehicle (ATV) accidents can have on young children. This November, Masiakos traveled to Australia to present lessons learned since enacting a state law that has dramatically decreased the number of ATV accident-related injuries and deaths in children throughout Massachusetts.

  • Honoring pioneers past and present

    Quality and cost are two of the most important drivers of innovation in health care today. At the MGH, the Bowditch Prize is awarded annually to individuals or groups who are able to achieve substantial improvement in both of these areas.

  • MGH and MGHfC celebrate passage of three child-safety laws

    MGH Hotline 11.12.10 On Oct. 21, members of the MGH and MassGeneral Hospital for Children (MGHfC) gathered with state legislators and advocates to commemorate the passage of three Massachusetts child-safety laws.

  • MGHers successfully advocate for injury-prevention state laws

    MGH Hotline 08.06.10 The caregivers at the MGH and MassGeneral Hospital for Children (MGHfC) support the health and well-being of adults and children in many ways. Recently, several hospital caregivers and administrators went a step further in their support of the health of their communities when they played important roles advocating for several injury-prevention state laws.

  • Sophia's Story

    At 29 weeks, Sophia O'Brien was born with multiple medical issues. But with help from her MassGeneral Hospital for Children team, she has grown into a healthy ballerina.

  • MGHfC residents visit the State House

    MGH Hotline 06.12.09 In what’s become an annual tradition, residents, fellows and staff from MassGeneral Hospital for Children (MGHfC) made a special visit to the gold-domed building down the street to advocate for legislation affecting children's health.

  • Post-trauma treatment

    MGH Hotline 4.3.09 It was just another soccer tournament for 14-year-old Megan Lund, a freshman at Needham High School, as she played on a field in Florida this past fall.

  • Shining more light on pediatric trauma

    New MassGeneral Hospital for Children trauma clinic helps kids recover.


Pediatric Surgery
55 Fruit Street
Boston, MA 02114-2696
Phone: 617-726-8839
Fax: 617-726-2167