The purpose of this study was to investigate the factors influencing sexual partner referral using the Attitude-Social influence self-Efficacy model as a guiding theoretical framework. The data was collected in an interview survey with 236 women and 190 men attending a sexually transmitted disease clinic in Kampala, Uganda. Intention, attitude, subjective norm, self-efficacy, and past behaviour in relation to partner referral as well as partner type were collected at time 1. At time 2 (1 month later), sexual partner referral was assessed. Intention, self-efficacy, and previous behaviour predicted partner referral for women whereas intention, partner type and previous behaviour predicted partner referral for men. For the women the strongest predictors for intention were self-efficacy followed by attitude and partner type. For the men the strongest predictor was attitude followed by partner type and self-efficacy. Social influence was a better predictor of intention for women than for men. An analysis of underlying cognitive beliefs discriminating those who referred and those who did not refer the sexual partner showed that attitudinal beliefs were the most important for men whereas self-efficacy beliefs were the most important for women. The targeting of the gender-based discriminatory beliefs in intervention may improve compliance with sexual partner referral.