Those who study sexual behaviour often rely on self-reported information from surveys. However, results from surveys may be inaccurate due to social desirability bias (SDB). One way to combat SDB is to change the mode of inquiry. Typically surveys are conducted using face-to-face-interviewing. The use of audio computer-assisted self-interviewing (ACASI) has been proposed as a better alternative. There is evidence from Africa, that use of ACASI may elicit more adequate reporting of sensitive sexual behaviours. Here we describe a sexual behaviour survey we conducted in three disadvantaged communities of Cape Town using ACASI methods.