With reference to the clinical courses of three patients treated at the Department of Surgery, National Institute of Oncology, Budapest, the literature on the diagnosis and treatment of peritoneal pseudomyxoma has been reviewed. The disease is considered to be a rare low grade malignancy. Abdominal ultrasonography, computer tomography and laparoscopy are of significance in the diagnosis of this disease which is yet confirmed usually during surgery. The treatment is principally surgical, the results of chemotherapy are modest. The disease has a slow course and is susceptible to recurrence. Despite of early diagnosis and radical surgery cure can be reached rarely.