Introduction: Medication adherence plays an important role in preventing the worsening of cardiovascular disease. Some factors associated with medication adherence are still unknown. Objective: This study aimed to determine the factors related to medication adherence in patients with coronary artery disease. Materials and Methods: A cross-sectional analytical study was performed on 367 cardiovascular patients by consecutive sampling. The patients were referred to the specialized cardiology clinic in Rasht City, Iran, from January 2019 to June 2020. A data collection form and questionnaires of cardiac anxiety, anxiety depression and stress, and medication adherence were used. The obtained data were analyzed by the Chi-square test, Fisher exact test, Kolmogorov-Smirnov test, Mann-Whitney U test, and logistic regression model. The significance level was considered less than 0.05. Results: Most samples were men (61.85%). The mean ± SD age of the samples was 59.9 ± 10.9 years. About 20.7% had high adherence, and 78.75% had moderate adherence. Factors related to medication adherence included employment or being retired (OR=4.0, 95%CI; 1-16.6, P=0.054), income level (OR= 5.1, 95%CI; 1.6-16.6, P=0.007), supplemental insurance (OR= 0.217, 95%CI; 0.07-0.66, P=0.007), living alone (OR= 10.187, 95%CI;1.980-52.404, P=0.005), living with spouse and children (OR= 3.776, 95%CI; 1.580-9.023, P=0.054), history of hyperlipidemia (OR= 3.2, 95%CI; 1.2-8.4, P=0.019), history of stent implantation (OR= 2.9 95%CI; 1.2-7, P=0.016), depression (OR=0.74, 95%CI; 0.66-0.83, P=0.0001), anxiety (OR= 1.3, 95%CI; 1.1-1.4, P=0.0001), avoidance (OR=0.69, 95%CI; 0.56-0.86, P=0.0001), attention (OR= 1.5, 95%CI; 1.2-1.8, P=0.0001), and medication complexity (OR= 2.7, 95%CI; 1-6.8, P=0.04). Conclusion: According to the identified related factors, it may be possible to decline anxiety and depression symptoms by improving the related factors and follow-up of care programs. As a result, cardiovascular patients are helped by preventing readmission, cardiac event, and mortality.