OBJECTIVES: To evaluate the effectiveness of the Community-based Hypertension Improvement Project (ComHIP) in increasing hypertension control. SETTING: Lower Manya Krobo, Eastern Region, Ghana. PARTICIPANTS: All adult hypertensive community members, except pregnant women, were eligible for inclusion in the study. We enrolled 1339 participants, 69% of whom were female. A total of 552 had a 6-month visit, and 338 had a 12-month visit. INTERVENTIONS: We report on a package of interventions where community-based cardiovascular disease (CVD) nurses were trained by FHI 360. CVD nurses confirmed diagnoses of known hypertensives and newly screened individuals. Participants were treated according to the clinical guidelines established through the project's Technical Steering Committee. Patients received three types of reminder and adherence messages. We used CommCare, a cloud-based system, as a case management and referral tool. PRIMARY OUTCOME: Hypertension control defined as blood pressure (BP) under 140/90 mm Hg. SECONDARY OUTCOMES: changes in BP and knowledge of risk factors for hypertension. RESULTS: After 1 year of intervention, 72% (95% CI: 67% to 77%) of participants had their hypertension under control. Systolic BP was reduced by 12.2 mm Hg (95% CI: 14.4 to 10.1) and diastolic BP by 7.5 mm Hg (95% CI: 9.9 to 6.1). Due to low retention, we were unable to look at knowledge of risk factors. Factors associated with remaining in the programme for 12 months included education, older age, hypertension under control at enrolment and enrolment date. The majority of patients who remained in the programme were on treatment, with two-thirds taking at least two medications. CONCLUSIONS: Patients retained in ComHIP had increased BP control. However, high loss to follow-up limits potential public health impact of these types of programmes. To minimise the impact of externalities, programmes should include standard procedures and backup systems to maximise the possibility that patients stay in the programme.