Most patients with coronary anomalies are asymptomatic. The knowledge of those variations could be important in regard to invasive catheter treatment or bypass surgery. In a retrospective study, the angiographic findings based on 4,016 patients (1985-1989) were analyzed concerning coronary anomalies and malformations. Of the patients studied, 39 (0.97%) had coronary anomalies, and in 26 of these patients it was an anomalous circumflex branch. In 14 cases, the circumflex branch arose from a separate origin in the left aortic sinus. In 11 patients the origin was from the proximal segment of the right coronary artery. A singular coronary artery was found in five patients, originating from the right aortic sinus in two patients and from the left aortic sinus in three patients. An origin of the left coronary artery from the pulmonary artery, a coronary fistula, or an origin of the left anterior descending coronary artery from the RCA could be found in only one patient. Unexpected findings during invasive procedures would suggest a possibly existing coronary anomaly, especially when main branches cannot be opacified by selective contrast medium injection.