A survey of 500 patients attending primary health care centres in Riyadh, Saudi Arabia was carried out to determine the prevalence and factors associated with self-medication practice. The results indicated that 35.4% of the respondents had practised self-medication past 2 weeks. Bivariate and multivariate analyses indicated that respondents who were young, male, having poor health status, reporting inconvenient access or dissatisfied with health care were more likely to practise self-medication. Health education campaigns, strict legislations on dispensing drugs from private pharmacies and increasing the quality of and access to health care are among the important interventions that might be needed in order to change the people's health seeking behaviour and protect them from the potential risks of self-medications.