Screening for STIs is worthwhile as it facilitates early detection and prompt treatment, and potentially minimises complications and long-term sequelae of infection. It also allows for the interruption of forward transmission, thereby reducing the risk of reinfection. Screening offers opportunities for patient education and counselling to effect behaviour change and, by decreasing prevalence rates, is of public health benefit. Screening is essential for detecting many STIs because of high rates of asymptomatic carriage. Here we consider common STIs, who to screen, and how to approach taking a sexual history.