Pseudomyxoma peritonei is an infrequent clinical entity, characterized by peritoneal implantations organized in cyst of mucine or free peritoneal mucine. Most arise from cystadenoma or cystadenocarcinoma of the ovary and appendix, and fewer from other tumours and locations. It is more common in females, and it is usually diagnosed over the fifth decade. Three cases of pseudomyxoma peritonei are presented, two associated to appendicular carcinoma and one to carcinoma of the ovary, and the data published about this disease are reviewed.