Extinction is a well-researched behavioural procedure that is used to reduce in frequency, or eliminate, behaviour that is judged to be inappropriate or excessive. Typically, the procedure is implemented contingent upon the exhibition of the behaviour targeted for change. In the present study, the effects of an accidental extinction procedure on pokey players' behaviour are discussed. Extinction is deemed “accidental” in that the procedure came into effect as the result of a power failure. Results demonstrate a gradual reduction in attempts to operate the poker machines over the extinction period, as well as an increase in the collateral behaviours of beverage (primary alcohol) consumption, cigarette lighting, and social interactions. Implications of this study for further research are discussed.