The objective of this work was to investigate the prevalence and determinants of medicines consumption in Fortaleza, Ceará, Brazil. A population-based cross-sectional study was carried out in a representative sample of 331 households. A total of 1,370 persons living in Fortaleza were interviewed from October 2002 to January 2003, and 1,366 were selected for this study. Consumers were defined as all persons having used one or more drugs during the preceding 15 days. The prevalence of medicine consumption was 49.7%. The following were the predictive factors for medicines consumption according to the multivariate logistic regression analysis: family income > 3 minimum wages, older age ( > or = 50), female gender, > or = 3 persons living in household, chronic disease, having a health insurance plan, and one or more visits to the doctor in the last three months. Prevalence of medication use was high in Fortaleza but was similar to that found elsewhere in Brazil and in other countries. Inequality in the access of medications was identified.