Previous reports of accidental ingestion of cannabis by children are rare. None has reported coma, although one described a stuporous state that required assisted ventilation. Over the past four years, the staff of British Columbia's Children's Hospital has managed six children with cannabis toxicity, three of whom presented in coma, including one with airway obstruction. Recurring diagnostic features included rapid onset of drowsiness, moderate pupil dilation, hypotonia, lid lag, and the presence of small granules or leaves in the mouth. Confirmation was obtained by positive urine screening for cannabinoids. The six cases described emphasize the need for emergency physician awareness of possible diagnostic criteria, the potential severity of intoxication, and the need for prevention through parent education.