Hypertension remains a major public health challenge globally, with suboptimal adherence to treatment and lifestyle modifications exacerbating cardiovascular risks. This study evaluates multidimensional adherence (medication, diet, and behavior) and its determinants among hypertensive patients in rural Northeast China. A cross-sectional study enrolled 6352 adults aged ≥ 40 years with diagnosed and poorly controlled hypertension from rural villages across five cities (Benxi, Chaoyang, Dandong, Donggang, and Fuxin) in Liaoning Province, Northeast China, using multistage cluster sampling. Adherence was assessed via standardized questionnaires, with logistic regression analyzing sociodemographic, clinical, and behavioral predictors. Medication adherence was reported by 73.7% of participants, while dietary and behavioral adherence rates were 10.5% and 29.3%, respectively. Ethnic disparities emerged, with Han Chinese exhibiting lower medication adherence (aOR = 0.485, 95% CI: 0.377-0.624). Cohabiting with children enhanced dietary adherence (aOR = 2.184, 95% CI: 1.854-2.573), whereas widowed status reduced both dietary (aOR = 0.698, 95% CI: 0.528-0.924) and behavioral adherence (aOR = 0.726, 95% CI: 0.595-0.887). Higher hypertension knowledge scores positively influenced all adherence domains ( < 0.05). Adherence among rural hypertensive patients is multidimensional, shaped by cultural, socioeconomic, and behavioral factors. Targeted interventions addressing dietary sodium reduction, family-based support, and health literacy improvement are urgently needed. This study underscores the importance of integrating region-specific strategies into hypertension management programs to mitigate cardiovascular morbidity in high-risk populations.