Abstract Objectives To assess the clinical impact of comprehensive medication management (CMM) services offered to geriatric and hypertensive patients in primary health care in Brazil. Methods A quasi-experimental study was carried out with patients followed up in primary care in three Brazilian cities (n = 346). McNemar’s test was used to assess the clinical impact of the service. Key findings A total of 1308 drug therapy problem (DTPs) were identified and 581 (44.4%) were resolved. Among the DTPs, the majority were related to non-adherence to therapy (23.9%; n = 313) or the need for additional medications (18.2%; n = 238). It was observed an increase in the proportion of people who had their blood pressure controlled at the last visit when compared with the first visit. Conclusions This study indicates that the CMM service can contribute to achieving blood pressure control in geriatric and hypertensive patients. The frequency of DTPs was high in the studied population, but many DTPs were resolved by pharmacists.