Xeroderma pigmentosum is a hereditary disorder characterized by the ear1y development of pigmentary changes, atrophy, keratoses, and carcinoma, predorninantly light exposed area skin. Two cases of xeroderma pigmentosum complicated. by basal cell Ca. were presented. The one was 15 years old male who had been suffered frorn pea to walnut sized multiple tumors and ulcers on the face with scattered brownish macuIes on the sun exposed area since about 9 years old of his age. The other was 22 years old maIe who had been suffered from the same skin lesions as the former on the face, neck and dorsum of hands. In both cases skin lesions aggravated during each summer seasons and there were on history of convulsions and other neurological symptoms Histopathological findings of tumors on both cases revealed typical findings of basal cell Ca.