Introduction and objectives <p>Cardiovascular diseases are one of the most common chronic diseases and disturb the performance and social, familial, and occupational relations of patients. Adherence to treatment influenced by various factors such as self-efficacy, beliefs and social adequacy.</p> Methodology <p>This study was conducted to determine the predictors of adherence to treatment in cardiovascular patients based on social adequacy. Study design was Analytical descriptive cross-sectional study. The research population included cardiovascular patients discharged from the treatment centers .sample size was estimated to be 275 patients. The participants were selected by stratified random sampling based on inclusion criteria. Data were collected by a demographic information form, Fellner’s Social adequacy Questionnaire, and Modanlo’s Treatment Adherence Scale. Data were analyzed by SPSS software using descriptive and analytic statistics. Descriptive statistics summarized scores, while Pearson correlations examined relationships, and multiple linear regression identified predictors of happiness, with significance at <i>p</i> &lt; 0.05.</p> Results <p>the mean total social adequacy score of the patients participating in the study was (232 ± 29). The highest and lowest scores among the dimensions were related to the Behavioral skills dimension (184 ± 23) and the Cognitive skills dimension (15 ± 2), respectively. There was a significant correlation between social adequacy and adherence to treatment (<i>p</i> = 0.001, <i>r</i> = 0.66). There was also a significant relationship between adherence to treatment and four dimensions of social adequacy(<i>p</i> = 0.001).</p> Conclusion <p>Conclusion: Given the significant relationship between social competence and adherence to treatment, it is essential for health professionals in the community to promote factors such as social competence in patients, which can help in planning adherence to the treatment regimen and lifestyle changes.</p>