The aim of this study was to characterise attitudes and social norms with respect to gambling among a population of adult Australians. A further aim was to evaluate whether gambling behaviour (as measured by its frequency) and problem gambling (as measured by its negative social effects on an individual) could be predicted by a model combining attitudes and social influences. With a sample of 215 late adolescents and adults, the Theory of Reasoned Action was found to significantly predict gambling frequency and problem gambling, with intentions predicting actual behaviour in both cases. Subjective norms only indirectly affected behaviour (through intention) in the case of problem gambling, but had both direct and indirect effects on gambling frequency, while attitudes to gambling predicted intentions, rather than directly predicting behaviour. Males were likely to gamble more often than females, and to judge their behaviour as a problem. Across the sample, although most had gambled at some time (89 per cent), gambling frequency and problem gambling were low, and attitudes and subjective norms with respect to gambling were a complex mixture of acceptance and rejection.