We aimed to identify determinants of condom usage and unsafe sex in women h
aving sex with a new partner. One hundred women attending either a genitour
inary medicine (GUM) clinic or a family planning clinic participated in the
study. Respondents were interviewed about last 3 new male partners, from t
he beginning of the sexual relationship through its development, if any. Da
ta analysis was primarily qualitative, quantitative analysis was conducted
where appropriate. Alternative contraceptive use was the most commonly repo
rted determinant of condom usage overall. The most commonly reported determ
inant of condom use for prophylaxis was the woman's perception of her partn
er and the risks he presented. Models of risky sexual behaviour have focuse
d on the individual's generalized estimation of risks of acquiring STDs. Ex
isting models are poor predictors of risky sexual behaviour. We propose tha
t it is the perceived risk presented by a particular individual partner, no
t global risk, which influences behaviour. An individual risk model is put
forward.