AIM: To examine gender differences in changes in physiological arousal as indexed by heart rate during fruit machine gambling while controlling for the confounding effect of movement and as a function of winning and losing, and to examine relationships between sensation-seeking, self-reported arousal during gambling, heart rate during gambling and loss of control of gambling behaviour. SAMPLE, DESIGN AND MEASUREMENT. Heart rate and subjective arousal were recorded in a sample of 22 male and 20 female fruit machine players before, during and after the gambling process. At baseline measures were taken of sensation seeking, self-reported arousal during gambling and loss of control of gambling. A simulation of the behaviour used to operate fruit machines was used during baseline measurement. FINDINGS. Significant increases in heart-rate over movement controlled baselines were observed within participants during gambling. However, for the losing group these differences were slight compared to the increases found when participants won during play. Furthermore, winning/losing was the only variable among a range of variables which was a significant predictor of heart-rate increase during play over a baseline control. Additionally heart rate levels of males and females behaved the same way in relation to the manipulations. Significant correlations between heart rate during play and the measures of both subjective arousal and sensation seeking were also present. CONCLUSION. Winning during gambling is essential in order to maintain increased heart rate levels over baseline after play. Subjective arousal and sensation seeking may be predictors of levels of arousal experienced during play.