Abstract: This study aimed to determine the effectiveness of a self-care program for Thais with uncontrolled hypertension leading to pre-stroke. The program was based on self-care behavior and blood pressure control. The samples were 98 purposively selected patients with uncontrolled hypertension receiving care at a hospital in the central part of Thailand. The samples were randomly assigned to either the experimental (n = 50) or control group (n = 48). Those in the experimental group received a 24-week self-care program and routine care, while those in the control group received only routine care. The self-care program consisted of education sessions that were used to increase the samples’ knowledge about, and ability to carry out self-care for controlling their blood pressure. Data were collected via interview-administered questionnaires and blood pressure measurements, before and after participation in the program. Data were analyzed utilizing descriptive statistics; Chi-square; Mann-Whitney U test; and, independent t-test. Results indicated the experimental group, 24 weeks after completion of the program, had a significantly higher mean rank of self-care behavior regarding medication-taking, dietary control, exercise, stress management, and risk behavior avoidance, as well as significantly lower mean blood pressure levels than the control group. Findings suggest the program was effective in enhancing samples’ knowledge to control their blood pressure and prevent a complication as pre-stroke.