A systematic search of costs associated with obesity or intervention program in Canada between 1990 and 2011 yielded 10 English language articles eligible for review.The majority of studies was prevalence-based or top-down costing; 40% had excellent quality assessed using the Quality of Health Economic Study scale. The aggregated annual costs of obesity in Canada ranged from 1.27 to 11.08 billion dollars. Direct costs accounted for 37.2% to 54.5% of total annual costs. Between 2.2% and 12.0% of Canada's total health expenditures were attributable to obesity. The average annual physician cost of overweight male ($ 427) and female ($ 578) adults was lower than that of obese male ($ 475) and female ($ 682) adults; this cost differential across weight status groups was comparable to that found in adolescents. The cost for implementation and maintenance of a school-based obesity prevention program was $ 23 per student.We observed high costs associated with overweight and obesity and modest costs for obesity prevention programs; however, no cost-effectiveness study of obesity interventions has been performed in Canada. Cost-effectiveness analyses of preventive programs that constitute incidence-based life-time modeling of costs and health outcomes from societal perspective are urgently needed.