Team-based care can improve hypertension control. The purpose of the present study was to evaluate blood pressure (BP) control 18 months following the discontinuation of a physician-pharmacist collaborative intervention. This was a retrospective analysis of patients who had previously participated in a prospective, cluster randomized, controlled clinical trial. Six community-based family medicine offices were randomized to control or intervention groups. Research nurses measured BPs using an automated device during the prospective trial. The research nurses then abstracted data from medical records, including BPs, medications, changes in therapy, and laboratory values for 18 months following the discontinuation of the 6-month prospective trial. The study included 228 patients in the control (n=146) or intervention (n=82) groups. The control group contained more patients with diabetes or chronic kidney disease (P<.013), were older (P=.047), and had more coexisting conditions (P<.001) than the intervention group. Systolic BP 9 months following discontinuation of the physician-pharmacist intervention was 137.2±18.2 mm Hg and 129.8±13.3 mm Hg in the control and intervention groups, respectively (P=.0015). BP control was maintained in 61 (41.8%) control patients and 55 (67.1%) intervention patients (P=.0003). At 18 months post-intervention, systolic BP was 138.1±20.4 mm Hg and 130.0±16.0 mm Hg in the control and intervention groups, respectively (P=.023). BP control was maintained in 53 (36.3%) control patients and 55 (67.1%) intervention patients at 18 months post-intervention (P<.0001). A sensitivity analysis was conducted to address the uneven distribution of patients with diabetes or chronic kidney disease, and the differences between groups were still significant. BP control rates remained significantly higher following a physician-pharmacist intervention compared with usual care for 18 months after discontinuation of the intervention. This model has the potential value as a useful long-term strategy to benefit patients with hypertension. J Clin Hypertens (Greenwich). 2011;13:431–437. ©2011 Wiley Periodicals, Inc.