The purpose of this study was to determine whether a transdermal nicotine patch will produce the same effects on performance and mood as cigarette smoking. The nicotine patch improved attentional processing and produced some improvements in memory. It produced the calming effects of smoking and induced feelings of happiness which were increased with smoking. These effects were obtained 6 h after application of the patch, showing that acute tolerance for these behavioural effects had not developed completely, if at all, after exposure to nicotine, although it is still possible that tolerance might occur with longer exposure.