Blood pressure (BP) control, BP reduction and the quality of life (QOL) of hypertensive patients monitored by a pharmacist in three primary care settings in Mahasarakham Province, Thailand were evaluated. Patients were randomly assigned into the treatment and the control groups. The treatment group received their usual care plus the attention of a pharmacist every month to monitor BP and provide pharmaceutical care and counseling. The control group just received their usual care. QOL was measured at the pretest and after six and 12 months. BP was compared between that obtained at the pretest and after 12 months. The results  after 12 months from 235 patients, 118 treatment and 117 control, showed that the proportion of BP control was significantly higher in the treatment group, 92 of 118, than in the control group, 76 of 117, p<0.05. BP reduction was significantly greater in the treatment group, 26.72±19.36 for systolic and 13.53±11.21 for diastolic, than in the control group, 12.32±21.55 for systolic and 9.75±11.23 for diastolic, p<0.05. There were significant differences between the groups in physical functioning and role of physical scales. A significant interaction in role emotional scales, and a significant difference between groups after 12 months were noted. Our results indicate that a pharmacist’s care of hypertensive patients in the primary care setting can increase BP control, BP reduction and patients’ QOL.