In a prospectively constructed study 29 patients with cardiac phobia were examined prior to hospitalization and again after a follow-up period of 2.5 years. When first examined a high percentage (82.8%) of these patients showed a depression in addition to suffering from anxiety symptoms. The findings demonstrate that an additional affective disorder constitutes a prognostically unfavorable factor, particularly in the case of a ‘secondary’ depression. Compared with patients suffering from a ‘primary’ depression these patients more frequently exhibited a chronic course of the depression (at the 1 % level of significance) and had a significantly smaller chance of being free of cardiophobic complaint (p = 0.002) at the last examination. An attempt to categorize cardiac phobia according to DSM-III revealed that the present classification does not provide a satisfactory solution. The frequent presence of a depression in these patients strongly indicates that a clarification of the controversial opinions which continue to exist with regard to a linkage between depressive disorders and anxiety disorders would need further research; in such studies it would seem preferable not to employ a hierarchic classification procedure, in view of the fact that all cross-sectional psychopathological symptoms should be taken into consideration. Our findings also point to the advisability of paying closer attention to course traits in studying this question.