['To analyse patterns of patient utilisation of the after hours service at Sydney Sexual Health Centre (SSHC).', 'A retrospective cross sectional database study compared all new daytime and after hours patients who registered for a medical consultation at SSHC between August 1994 and February 1995. Daytime and after hours attenders were compared using demographic and behavioural factors and for prevalence of STDs and HIV using logistic regression analysis.', 'Of the 1662 eligible patients, 1362 (81.9%) attended during daytime hours, and 300 (18.1%) attended after hours. There was no significant difference in after hours attendance between patients living in inner compared with outer metropolitan zones. Using logistic regression analysis, being female (p = 0.0008), being between 20 and 39 years of age (p = 0.008), being employed (p < 0.001), and having no previous STD/genitourinary condition (p = 0.034) were the factors significantly associated with after hours attendance.'] Do young working women utilise the after hours service at Sydney Sexual Health Centre?