In this article, the authors review research to identify bullying as a critical public health issue for Canada. Drawing from recent World Health Organization surveys, they examine the prevalence of Canadian children and youth involved in bullying others or being victimized. There is a strong association between involvement in bullying and health problems for children who bully, those who are victimized and those involved in both bullying and being victimized. Health problems can manifest as physical complaints (e.g., headaches), mental health concerns (e.g., depression, anxiety) and psychosocial problems (e.g., substance use, crime). In Canada, there has recently been a disturbing incidence of Canadian children who have committed suicide as a result of prolonged victimization by peers. Healthcare professionals play a major role in protecting and promoting the health and well-being of Canadian children and youth. Given the significant mental and physical health problems associated with involvement in bullying, it is important that clinicians, especially primary care healthcare professionals, be able to identify signs and symptoms of such involvement. Healthcare professionals can play an essential role supporting children and their parents and advocating for the safety and protection for those at risk. By understanding bullying as a destructive relationship problem that significantly impacts physical and mental health, healthcare professionals can play a major role in promoting healthy relationships and healthy development for all Canadian children and youth. This review provides an overview of the nature of bullying and the physical and psychological health problems associated with involvement in bullying. The review is followed by a discussion of the implications for health professionals and a protocol for assessing the potential link between bullying and a child's physical and psychological symptoms.