OBJECTIVE: To analyse the links between other people's drinking and mental health and to explore the effects on mental health of heavy and problematic drinkers both within and outside spousal relationships. DESIGN, SETTING AND PARTICIPANTS: A secondary analysis of data obtained as part of the Alcohol's Harm to Others survey from 2622 randomly sampled Australian adults interviewed by telephone between October and December 2008. MAIN OUTCOME MEASURES: Self-reported anxiety or depression and satisfaction with mental wellbeing; the presence of heavy and problematic drinkers in respondents' lives. RESULTS: Identification of at least one heavy drinker in the respondents' social network of friends, family and co-workers was significantly negatively associated with self-reported mental wellbeing and anxiety or depression. If the heavy drinker was identified by the respondent as someone whose drinking had had a negative impact on their life in the past year, the adverse effect on mental wellbeing and anxiety was much greater. CONCLUSIONS: Our findings support a causal pathway between alcohol use and mental health problems by way of someone else's drinking. The association with adverse mental health is substantial regardless of the type of relationship an individual has with the heavy drinker whose drinking has had an adverse effect on them.