Diffuse telangiectatic type of pulmonary arteriovenous malformation (AVM) is an uncommon disease entity in which numerous small arteriovenous connections occur throughout the lungs. It has rarely been confirmed by pulmonary angiography. We report a case of diffuse telangiectatic pulmonary AVM occurring in a patient with dyspnea and confirmed by CT using the slab maximum intensity projection (MIP) technique and conventional direct pulmonary angiography.