The aim of the study was to evaluate the role of 64-row CT in the diagnostic workup of patients with chronic thromboembolic pulmonary hypertension (CTEPH) using digital substraction angiography (DSA) as the method of diagnostic reference. CT and DSA studies of 27 patients (54 main, 162 lobar and 540 segmental arteries) with a clinical suspicion of CTEPH were included in this retrospective and blinded analysis. Axial images and multiplanar thin maximum intensity projections (MIPs) (3mm) were consequently used for exact image interpretation whereas additional reconstructed thick MIPs gave an overview of the entire vascular tree comparable to DSA. Sensitivity and specificity of CT regarding CTEPH-related pathological changes in general were 98.3% and 94.8% at main/lobar level and 94.1% and 92.9% at segmental level, respectively. Sensitivity and specificity of CT regarding the different pathological criteria of CTEPH (complete obstruction, intimal irregularities, bands and webs, indirect signs) were 88.9-100% and 96.1-100% at main/lobar level and 84.3-90.5% and 92-98.7% at segmental level, respectively. Our results show that CT is an accurate and reliable non-invasive alternative to conventional DSA in the diagnostic workup in patients with CTEPH.