We experienced a case of usual interstitial pneumonia associated with primary biliary cirrhosis and psoriasis vulgaris. The subject was a 66-year-old female who had suffered from dry cough. Her chest X-ray examination revealed diffuse interstitial shadows on both lung fields. Usual interstitial pneumonia was diagnosed after video-associated thoracic surgery. Psoriasis has occurred since her 40s and has been diagnosed clinically without histological examination. The diagnosis of primary biliary cirrhosis was established by elevated biliary enzymes, the positivity of anti-M2 antibody, and histological examination of liver obtained by needle biopsy. She had not suffered from Sjogren's syndrome. Because primary biliary cirrhosis and psoriasis vulgaris are both caused by autoimmune mechanisms, they occur simultaneously in rare cases. However, a case in which all three of these diseases coincided has never been reported; thus we report this patient.