This paper reviews common law and statutory developments in the treatment of children as witnesses in Canada's criminal justice system, where children who are victims of abuse testify with increasing frequency. Historically, children were regarded as inherently unreliable witnesses, and there were no provisions to accommodate their needs and vulnerabilities; this treatment by the justice system contributed to the abuse and exploitation of children. Reflecting a growing body of research on child development, and a better understanding of the effects of the court process on children, over the past quarter century there have been substantial reforms in the law and the administration of justice. The law now better reflects what is known about the competency of child witnesses, as well as about their vulnerabilities. The paper includes a review of legislation and leading precedents, and a summary of the responses of Canadian judges to a survey about the most recent legislative reforms. The case law and survey reveal that judges are generally supportive of the reforms.