This study examined the associations of cannabis use, alcohol use and alcohol problems with probable anxiety and mood disorders (AMD) in young, middle-aged and older adults. Method: Data are based on the CAMH Monitor, an ongoing cross-sectional telephone survey of Ontario adults aged 18 years and older. For the purposes of the current study, a merged dataset from the years 2001 through 2009 inclusive was separated into three individual datasets: 18-34 year olds (n=4,211), 35-54 year olds (n=7,874), and 55 years of age and older (n=6,778). The survey included the 12-item version of the General Health Questionnaire, which provides a measure of probable AMD for the general population. Logistic regression analyses examined the odds of probable AMD in three age groups associated with alcohol measures (number of drinks per day and alcohol problems (AUDIT 8+)) and cannabis use, while controlling for self-reported physical health, religious service attendance, and demographic factors. Due to listwise deletion, the logistic regression models were based on reduced samples. Results: Lifetime cannabis use and past year cannabis use predicted probable AMD in young and middle-aged adults, but only lifetime cannabis use predicted probable AMD among older adults. Alcohol problems predicted probable AMD among middle aged and older adults, but not among younger adults. No consistent link between recent alcohol consumption and probable AMD was observed. Conclusion: These analyses suggest that the impact of alcohol and cannabis use and problems on probable AMD may differ across age groups.