The aim of this study was to translate the Cardiac Depression Scale into the Slovenian language and test its validity and reliability on Slovenian patients with heart disease. A total of 272 patients with heart disease who underwent elective coronary angiography at Celje General Hospital participated in this study. We used the Slovenian Cardiac Depression Scale (S-CDS), the Spielberger State Anxiety Inventory (STAI-S), and the Center for Epidemiologic Studies Depression Scale-20 (CES-D) to collect data. An exploratory and confirmatory factor analysis, internal consistency, test-retest reliability, and concurrent validity were performed. Cronbach's alpha for the total scale was 0.92 and the test-retest reliability was 0.71. Exploratory factor analysis confirmed six factors, accounting for 61% of the total variance. The confirmatory factor analysis indicated that a two- and one-factor solution had acceptable goodness-of-fit measures. However, we kept a more parsimonious one-factor method, given a high correlation between the two factors and the theoretical background in previous studies. Concurrent validation against the CES-D and the STAI-S showed moderate to strong correlations. The S-CDS is a reliable and valid instrument for screening for depression in Slovenian patients with heart disease.