This study establishes preliminary validation of a measure that assesses hypertension self-care activities with clinical blood pressure (BP). The Hypertension Self-Care Activity Level Effects (H-SCALE) was administered to patients with hypertension to assess levels of self-care. Patients (n=154) were predominantly female (68.6%) and black (79.2%). Greater adherence to self-care was associated with lower systolic and diastolic BP for 5 of the 6 self-care behaviors. Medication adherence was correlated with systolic BP (r=−0.19, P<.05) and weight management adherence was correlated with diastolic BP (r=−0.22, P<.05) after controlling for other covariates. Increased adherence to recommended dietary practices was strongly correlated with higher systolic (r=0.29, P<.05) and diastolic BP (r=0.32, P<.05). The H-SCALE was acceptable for use in clinical settings, and adherence to self-care was generally aligned with lower BP. Assessment of hypertension self-care is important when working with individuals to control their BP.