Mary Ellen Turpel-Lafond examined case files on 15 suicides and 74 attempted suicides by young people over three years.
Turpel-Lafond says most of them had experienced severe trauma from family violence, abuse, neglect and their parents' mental health and addictions issues before coming into government care, when their situation often deteriorated more.
"Then, their experience when they came into the system, instead of addressing the trauma, often compounded the traumas," Turpel-Lafond said.
"The Ministry of Children and Families has really not met the needs there. So I'm quite concerned about that and that's why I'm issuing this report."
Turpel-Lafond is promising a comprehensive report on B.C.'s child and youth mental health care system next year.
In the meantime, she is asking the province to immediately address past trauma many of these youth experience.