Background: CT pulmonary angiography is the diagnostic procedure of choice for non-massive pulmonary embolism. Aim: To assess the diagnostic yield for thromboembolic disease of CT pulmonary angiography and venography using a 64- slice multidetector tomography. Material and Methods: Prospective study of patients with a clinical suspicion of thromboembolic disease, subjected to CT pulmonary angiography and venography. The presence and location of pulmonary thromboembolism, of isolated or concomitant deep venous thrombosis and of other significant radiological findings, were registered. Results: A 64-MDCT scanner was performed to 893 patients and thromboembolic disease was demonstrated in 240. Pulmonary thromboembolism was diagnosed in 218 patients. It was concomitant with deep venous thrombosis in 79 patients (36%) and isolated in the rest. Thirty fve of the 218 patients with pulmonary thromboembolism had radiological evidence of right ventricular overload. Twenty two patients (10%) had an isolated deep venous thrombosis. In 65 patients with pulmonary thromboembolism (30%) a possibly new or old malignant lesion, was observed. Seventy one of 653 patients without evidence of thromboembolic disease had potentially pathological findings on CT. Conclusions: The combined use of CT pulmonary arteriography and venography using a 64 MDCT scanner increases the diagnostic yield of the procedure for thromboembolic disease. It also allows the diagnosis of other related conditions, specially malignant tumors.