Sex, sexuality and sexual health beliefs are individual, impacting on physical and mental health. Sexual history taking is rarely taught in General Practice (GP). However, 'sex' is routinely relevant in this setting. Birmingham students practice discussing sexual history with a simulated-patient in GP. Simulated-patient inclusion in teaching/assessment is well-documented, but no study evaluating the impact of role play on attitudes to people who need STI testing was identified. We aimed to identify whether facilitated simulations featuring a sexual history scenario effected change in students' attitudes towards people who need STI testing. A randomised-controlled-trial was used to compare attitudinal scores between students exposed to an STI role play and a control group who did not receive the role-play teaching until after data capture. There were no significant differences in attitude, either in negative or positive direction, observed between control and intervention groups. Ethnicity was a significant variable, with white-British students self-reporting more positive attitudes. Twenty five percent students admitted personal STI exposure. Again response varied significantly between ethnic groups (the white-British group reporting 4× the exposure). Females reported more positive attitudes than males, most marked in relation to 'willingness to date' someone who admitted to STI testing.