This study provides a comprehensive estimate of the economic burden of mental health problems in Canada in 1998. In particular, it estimates the cost of non-medical services that have not been previously published and the value of short-term disability associated with mental health problems that were previously underestimated according to the definitions used here. The costs of consultations with psychologists and social workers not covered by public health insurance was $278 million, while the value of reduced productivity associated with depression and distress over the short term was $6 billion. Several data limitations suggest that these are underestimates. The estimated total burden of $14.4 billion places mental health problems among the costliest conditions in Canada.