--- - |2+ Abstract Background A high proportion of cardiac patients suffers from depression, which is an antecedent for suicidal ideation. This study identifies clinical vulnerabilities for suicidal ideation in cardiac patients. Methods The primary outcome of the study was severity of suicidal ideation as measured with the Patient Health Questionnaire (PHQ‐9) item No. 9. Covariates were demographics, cardiac characteristics (i.e., Canadian Cardiovascular Society angina rating of chest pain and New York Heart Association rating of shortness of breath), depression (PHQ‐8,i.e., PHQ‐9 minus item No. 9), anxiety (Generalized Anxiety Disorder‐7, GAD‐7), somatic symptoms (PHQ‐15), illness perception (Brief‐Illness Perception Questionnaire), and health‐related quality of life (EuroQol‐5D, EQ 5D). Results Data from 1,976 patients were analysed. At least 14% (95% CI [12%, 16%]) of patients indicated suicidal ideations within the last 2 weeks. Bivariate analyses yielded associations between suicidal ideation and higher levels of depression severity, anxiety severity, somatic symptom burden, chest pain, shortness of breath, negative illness perceptions, reduced health‐related quality of life, and a higher probability of living alone (all p < 0.001). A multivariable ordinal regression revealed depression severity and anxiety severity to show the highest associations with suicidal ideation (ORPHQ‐8 = 1.22, p < 0.001; ORGAD‐7 = 1.09, p < 0.001). Having a defibrillator implant was associated with a lower probability of suicidal ideation (OR = 0.27, p = 0.017). Conclusions This study identified several clinical vulnerabilities of suicidal ideation. The results stress the importance of screening for suicidal ideation in clinical practice. - Clinical Psychology & Psychotherapy, EarlyView.