The purpose of this study was to translate the current Cardiac Depression Scale into a Thai language version and then examine its validity and reliability. Responses to the 26-item Thai version of the Cardiac Depression Scale (CDS) were collected from 243 Thai subjects with cardiac disease. The data met the significant assumptions for exploratory factor analysis. Hypothetical examples were generated and exploratory factor analysis was performed. Exploratory factor analysis revealed seven components to determine cardiac depression that may manifest as sleep disorder, uncertainty, moodiness, hopelessness, inactivity, anhedonia, and cognition. The instrument showed acceptable validity and reliability. In conclusion, the Cardiac Depression Scale can be used in the clinic to measure depression among Thai patients with cardiac disease.