Background <p>The management of cardiovascular (CV) diseases is considerably hindered by the presence of anxiety disorders, which act as a significant barrier to medication adherence. This systematic review and meta-analysis aim to synthesize existing evidence on the relationship between anxiety and medication adherence in individuals with CV diseases.</p> Methods <p>A systematic search was conducted across five major databases from inception to 2025. The methodological quality of the included studies was assessed using the National Institutes of Health (NIH) quality assessment tool. A random-effects meta-analysis was conducted utilizing Comprehensive Meta-Analysis software (version 3), with with <i>p</i> &lt; 0.05 indicating significance.</p> Results <p>A total of 23 studies were selected, including 18 with cross-sectional and five with a longitudinal study design. The combined sample size was 72,815 participants, with an average age of 60.7&#xa0;years and 51.7% were male participants. Majority of studies (<i>n</i> = 15) reported a negative association between anxiety and cardiovascular (CV) medication adherence. Meta-analysis (<i>n</i> = 20) further supported this overall negative association (SMD = -1.087, 95% CI [-1.469, -0.705], <i>p</i> &lt; 0.001) which was also evident across clinical subgroups: hypertension (SMD = -0.648, 95% CI [-1.293, -0.004], <i>p</i> = 0.049), congestive heart failure (SMD = -0.51, 95% CI [-0.92, -0.10], <i>p</i> = 0.02), and ischemic heart disease (SMD = -2.322, 95% CI [-3.498, -1.146], <i>p</i> &lt; 0.001).</p> Conclusion <p>This review primarily contributes to the understanding of negative association between anxiety and medication adherence in the context of CV diseases. However, the predominance of cross-sectional designs, and substantial heterogeneity necessitate cautious interpretation of these findings.</p>