The application of open intraoperative intraperitoneal chemotherapy following cytoreductive surgery for the treatment of pseudomyxoma peritonei or peritoneal carcinomatosis requires safety precautions for the medical and non-medical personnel. In agreement with already existing rules, precautions were established which result in an optimum of safety. These concern the preparation of the cytostatic drugs, the application in the operating room as well as personal precautions intra- and postoperatively. After the establishment of theses recommendations, 22 patients were treated with open intraperitoneal chemotherapy in 1.5 years without any severe accidents. Therefore, a safe intraoperative use of cytotoxic drugs is possible. At the moment, the indication for such an approach may be given in peritoneal carcinomatosis from appendix, colon or ovarian cancer. In the future, an adjuvant application in other gastrointestinal malignancies (e.g. T3/T4 gastric carcinoma) may be considered.