Numerous studies in North America, Europe and Australia have linked depression to increased risk of morbidity and mortality in coronary artery disease (CAD). Although the co-morbidity of depression and CAD is well documented in the western world, little work on the subject has been carried out in Asia. Differing depression presentations in Asia necessitate the use of culture-specific depression rating scales. This study sought to determine whether the correlation between CAD and depression documented in western countries also exists in an Asian nation: Thailand. It was hypothesized that rates of depressive symptoms were higher in Thai inpatients with either unstable angina or recent myocardial infarction than in Thai inpatients with non-cardiac (orthopedic) complications. A 15-question culturally-appropriate self-rating depression inventory was administered to 56 Thai inpatients33 cardiac and 23 orthopedicat two public and one private hospital in Bangkok. Subjects were asked to rate each of the fifteen items on a scale from 0-3 based on how they felt during the past week. Higher scores correlated with greater depressive symptoms. Five cardiac and two orthopedic patients were excluded from the final analysis because of past medical history of major depressive disorder. Of the remaining 49 patients, questionnaire scores ranged from 1 to 23, with a mean depression score of 9.00 (S.E.M.=.84). Cardiac patients showed significantly greater depressive symptoms than their orthopedic counterparts at one public and one private hospital: Ramathibodi Hospital (P=.01) and Bangkok General Hospital (P=.005), respectively. For cardiology patients, the three highest scoring items were early insomnia (Mean = 1.39), late insomnia (Mean = 1.25) and loss of appetite (Mean = 1.04). For orthopedic patients, the three highest scoring items were work inhibition (Mean = 1.05), anxiety (Mean = .86), and early insomnia (Mean = .86). On post-hoc analysis, it was shown that patients in hospital units with air-conditioning showed significantly fewer depressive symptoms than patients without air-conditioning (P=.003), where the daily temperature often reached 115[degrees]F. Rates of depressive symptoms did not differ in accordance with education level (P=.15), gender (P=.49) or age (P=.29). In conclusion, this study provides some evidence that Thai inpatients hospitalized for severe CAD have greater depressive experience than their orthopedic counterparts. This finding supports our hypothesis that depression and CAD are linked in Thailand as they are in western countries.