Peritoneal carcinomatosis is a common evolution of digestive-tract cancer with a poor prognosis. However, a small subgroup unrelated to the digestive tract or any other primary cancer has a relatively better prognosis, especially in women. There are no published data to recommend a treatment regimen for this distinct group. Here we present two women with peritoneal carcinomatosis of unknown origin, who responded to chemotherapy with paclitaxel plus carboplatin. One underwent an exploratory laparotomy and was confirmed to have no residual tumor. The other had complete resolution of ascites and omentum lesions confirmed by radiological examination. From this experience we propose that paclitaxel plus carboplatin is an effective combination regimen for this unique subset of patients. Further prospective trials should be conducted to substantiate this proposal in a larger patient cohort.