Predicting gender-specific effects of the adultification of the juvenile justice system is complicated by the lack of research on young female offenders. Some of the research questions that must be addressed before the effect of adultification on young female offenders can be determined are how policy will affect the increasing number of girls involved in moderately serious personal injury offenses and whether the mental health outcomes for girls will be affected by the adultification of youth justice. The authors argue that a separate system of youth justice that focuses on the specific needs of offending youth, including gender-specific needs, must be maintained. For most of the 1900s, youth justice was a welfare-based system that viewed youthful offending as a symptom of social disadvantage and/or poor parenting. By the mid-1960s a clear change in juvenile justice policy had occurred. Deterrence and public protection became the priorities of juvenile justice. This trend in juvenile justice policy is reflected in Canada's YCJA. Because of their distinctive offending patterns, the effect of the adultification of the juvenile justice system on male and female young offenders may be different. 2 figures and 51 references