This study was to test a model explaining the influence of financial status, education, social support, symptom severity, barriers, knowledge, depression, and self-efficacy on medication adherence among persons with post-acute myocardial infarction. The use of multi-stage cluster sampling method involved 348 patients from 9 regional hospitals in Thailand. The results revealed the hypothesized model fit to the empirical data and explained 20% of the variance of medication adherence ( 2 = 5.87, df = 5, p < .43, Chi-square/df = 0.97, GIF = 0.99, RMSEA = 0.065, AGFI = 0.97). Depression was the most influential factor affecting medication adherence, and had a negative direct effect (-.40, p < .05), followed by self-efficacy and barriers (.17 and .10, p < .05, respectively). These findings suggest that nurses should understand that depression, barrier, and selfefficacy are important factors to be considerate to improve medication adherence and improve the quality of life of Thai postmyocardial infarction patients.