Two patients developed isolated Candida albicans peritonitis in association with intraabdominal malignancy. Although additional factors predisposing to the development of fungal peritonitis were present, we postulate that tumor-related local factors permitted fungi to cross the gut wall and to enter the peritoneum, where the host immune status determined whether the infection spread. These two cases are the sixth and seventh reported cancer patients who developed fungal peritonitis, but the first two who had the fungal infection localized to the peritoneum; and this is the first report known to us specifically associating intraabdominal malignancy and fungal peritonitis. Patients who develop fungal peritonitis may have a primary or metastatic intraabdominal malignancy, and fungi should be considered as a cause of peritonitis in cancer patients.