The numbers of individuals developing problems with gambling is on the increase. This study explored the nature of problem gambling through an analysis of the reported experiences of problem gamblers. A grounded theory approach involving the analysis of material from 14 male treatment seeking gamblers resulted in the identification of three main categories. These were emotion, control and costs of gambling. Central to the experience of all participants was the emotional nature of gambling, gambling being used either to induce or suppress arousal with a marked lack of other coping strategies. Control of gambling was an issue only in the context of efforts at behaviour change. Gambling costs were extensive including financial, relationship and emotional costs. Repeated failure of efforts at control resulted in tolerance of high levels of costs and repeated cycles of gambling. Patterns of interactions between these factors are identified in the emergent theory.