The public health system in Brazil is insufficient to provide basic pharmaceutical and medical care to the population. Currently, some herbal therapy programs are being developed in primary healthcare services to supply the communities lacking basic medicines. To investigate the use of herbal medicines in primary health care in Maracanaú, a northeast Brazilian city. A descriptive cross-sectional study was conducted in family health care units in Maracanaú during August and September of 2002. Two hundred twenty-six patients were interviewed via structured questionnaire. Descriptive statistical analysis was accomplished using sample size and proportions. Chi2 and Student's t-tests were used to compare percentages and means, respectively. Among the 226 patients interviewed, 144 (63.7%) reported previous use of herbal medicines. Among those, 131 (90.9%) observed therapeutic benefits from herbal medicines. We identified 10 types of herbal medicines in the prescriptions, including syrups, dyes, capsules, and ointments, for the treatment of respiratory problems (63.8%), skin conditions (15.3%), diabetes mellitus (11.4%), and other illnesses. Further, we observed that some herbal medicines were not being produced during the study period and that several patients were not aware of the fact that they were receiving herbal medicine. Data support the use of herbal therapy in primary health care in Maracanaú. However, there is a need to conduct further study on the efficacy and safety of these herbal medicines, as well as on their quality control.