Two cases of localized pseudomyxoma peritonei in the female pelvic cavity associated with a ruptured appendiceal mucocele and ovarian involvement that mimicked ovarian carcinomatous peritonitis were evaluated. Subtle omental irregularity adjacent to the cecum may suggest the hidden appendiceal origin reflecting localized carcinomatous peritonitis caused by the occult rupture of the mucocele. Mucinous fluid-like materials were localized in the pelvic cavity with scalloping of the uterus, which may be the diagnostic finding of pseudomyxoma peritonei.