Background: Hypertensive disorders during pregnancy remain major causes of maternal and neonatal morbidity and mortality. Effective blood pressure control requires not only medical treatment but also family support to improve maternal adherence to medication and antenatal care. Objective: This study aimed to determine the effect of a family-based mentoring innovation on hypertension control among pregnant women at South Amuntai Primary Health Center. Methods: A quantitative quasi-experimental study with a pretest–posttest control group design was conducted among 60 pregnant women diagnosed with hypertension. Participants were selected using purposive sampling and allocated into intervention (n=30) and control (n=30) groups. Data were collected through blood pressure measurements, structured questionnaires, observation sheets, and medical records. Data were analyzed using univariate analysis, paired and independent t-tests, and multivariate linear regression with a significance level of 0.05. Results: The intervention group showed a greater reduction in mean systolic blood pressure (15.8 mmHg) than the control group (4.3 mmHg). Significant improvements were also observed in maternal treatment adherence and family participation after the intervention (p<0.05). Multivariate analysis demonstrated that family-based mentoring had a statistically significant effect on hypertension control after adjustment for potential confounding variables. Conclusion: Family-based mentoring effectively improves hypertension control among pregnant women by strengthening treatment adherence, routine health monitoring, and active family participation. This intervention has potential as an evidence-based approach to strengthen maternal healthcare services at primary healthcare facilities and support the prevention of pregnancy-related complications associated with hypertension. The findings highlight the importance of integrating families into hypertension management at healthcare facilities.