Objective/Design. We performed a systematic review of studies that evaluate the role of gynecological cancer surveillance in women who carry a hereditary nonpolyposis colorectal cancer (HNPCC) mutation or belong to a family that fulfills the criteria for HNPCC. Methods. The PubMed database and a clinical trials database were used to identify relevant studies. We included studies that reported results of gynecological cancer surveillance in women who carry a HNPCC mutation, belong to a family in which a HNPCC mutation was detected or belong to a family fulfilling the Amsterdam II criteria. Main Outcome Measures. Number and stage of cancers, interval cancers and cancer precursor states detected at screening. Results. Five studies fulfilled our review criteria. Surveillance modalities for endometrial cancer included transvaginal ultrasound combined with endometrial sampling when indicated, or transvaginal ultrasound with a routine endometrial biopsy, and, in certain studies, the tumor marker CA-125. The highest yield of pathological findings in surveillance visits, from 5 to 6.5%, occurred in studies that included routine endometrial biopsies. Without a routine sampling, 7/14 cancers and 11/18 hyperplasias would have been missed. One case of advanced ovarian cancer was detected at surveillance. Conclusions. Currently available published studies on gynecological cancer surveillance in women with HNPCC do not adequately allow for evidence-based clinical decisions. Detection of endometrial cancer or hyperplasia in nonsymptomatic women belonging to an HNPCC family is improved by adding routine endometrial sampling along with transvaginal ultrasound for surveillance visits. No benefit was shown for ovarian cancer surveillance.