Knowledge of STI symptoms in men and women, by sex of respondent. The 399 men and 410 women who had ever heard of STIs were asked to name, without prompting, STI symptoms in men and women. Results for the five STI symptoms most frequently named are presented; we also present the proportion that name a combination of key STI symptoms in men, in women, and in both men and women. Key symptoms were defined as penile discharge and genital ulcers/open sores in men, and vaginal discharge and genital ulcers/open sores in women. Items where the proportions differ significantly between genders are annotated (*** p < 0.001, ** p < 0.01, * p < 0.05).