INTRODUCTION: Heterotaxy or situs ambiguus is a rare congenital disorder, characterized by abnormal situs with either left or right isomerism that usually coincides with A complex malformation. The classic left isomerism or bilateral left-sidedness or heterotaxy syndrome with polysplenia implies that patients have bilateral bilobed lungs, bilateral pulmonary atria, a centrally located liver, a stomach in indeterminate position, and multiple spleens, occasionally associated with interruption of the inferior cava with azygos or hemiazygos continuation. CASE REPORT: We present a case of situs ambiguus associated with severe heart and vascular abnormalities in a 25-year-old male patient. On the admittance to our clinic the patient had history of biliary colic, moderate jaundice of the conjunctive and sclerae, and severe central cyanosis. The echocardiography revealed a large atrial septal defect, complete absence of the interventricular septum resulting in the single ventricle and the inversion of atria. The angiography obtained the hypoplastic inferior vena cava continuing with azygos vein that flowed into the left superior vena cava. The computerized tomography scans showed three splenuli in the right upper quadrant of the abdomen, and a single gallstone appeared in the left-positioned gallbladder. The contrast radiography showed complete transposition of the guts and stomach. DISCUSSION AND CONCLUSION: To our knowledge, our patient with described severity of the anomalies had the longest life span in this part of Europe, although the longer survivors have been described in the other parts of the world. Furthermore, clinical characteristics of both left and right isomerism have been obtained in the patients with anatomically pronounced left isomerism.