Although the efficacy and effectiveness of lifestyle modifications and antihypertensive pharmaceutical treatment for the prevention and control of hypertension and concomitant cardiovascular disease have been demonstrated in randomized controlled trials, this scientific knowledge has not been fully applied in the general population, especially in low-income communities. This article summarizes interventions to improve hypertension management and describes the rationale and study design for a cluster randomized trial testing whether a comprehensive intervention program within a national public primary care system will improve hypertension control among uninsured hypertensive men and women and their families. We will recruit 1,890 adults from 18 clinics within a public primary care network in Argentina. Clinic patients with uncontrolled hypertension, their spouses and hypertensive family members will be enrolled. The comprehensive intervention program targets the primary care system through health care provider education, a home-based intervention among patients and their families (home delivery of antihypertensive medication, self-monitoring of blood pressure [BP], health education for medication adherence and lifestyle modification) conducted by community health workers and a mobile health intervention. The primary outcome is net change in systolic BP from baseline to month 18 between intervention and control groups among hypertensive study participants. The secondary outcomes are net change in diastolic BP, BP control and cost-effectiveness of the intervention. This study will generate urgently needed data on effective, practical and sustainable intervention programs aimed at controlling hypertension and concomitant cardiovascular disease in underserved populations in low- and middle-income countries.