After heart transplantation (HTx), non-adherence to immunosuppressants (IS) is associated with poor outcomes; however, intentional non-adherence (INA) is poorly understood regarding its international variability in prevalence, contributing factors and impact on outcomes. We investigated (1) the prevalence and international variability of INA, (2) patient-level correlates of INA, and (3) relation of INA with clinical outcomes. Secondary analysis of data from the BRIGHT study-an international multi-center, cross-sectional survey examining multi-level factors of adherence in 1,397 adult HTx recipients. INA during the implementation phase, i.e., drug holiday and dose alteration, was measured using the Basel Assessment of Adherence to Immunosuppressive Medications Scale; ©; (BAASIS; ©; ). Descriptive and inferential analysis was performed with data retrieved through patient interview, patient self-report and in clinical records. INA prevalence was 3.3% (; n; = 46/1,397)-drug holidays: 1.7% (; n; = 24); dose alteration: 1.4% (; n; = 20); both: 0.1% (; n; = 2). University-level education (OR = 2.46, CI = 1.04-5.83), insurance not covering IS costs (OR = 2.21, CI = 1.01-4.87) and barriers (OR = 4.90, CI = 2.73-8.80) were significantly associated with INA; however, clinical outcomes were not. Compared to other single-center studies, this sample's INA prevalence was low. More than accessibility or financial concerns, our analyses identified patient-level barriers as INA drivers. Addressing patients' IS-related barriers, should decrease INA.