Background: To assess the clinical value of peritoneal washing cytology (PWC) in women with BRCA1 or BRCA2 mutations and women from a family with hereditary breast and/or ovarian cancer (HBOC) undergoing risk-reducing salpingo-oophorectomy (RRSO) in detecting primary peritoneal cancer (PPC) or occult ovarian/fallopian tube cancer. Methods: A retrospective study of patients with known BRCA1 or BRCA2 mutation or HBOC who underwent RRSO at the Erasmus Medical Centre, Rotterdam, The Netherlands between January 2000-2014. Patients with an elevated risk of malignancy prior to the procedure were excluded from primary analysis (elevated CA-125, an ovarian mass, abdominal pain or another gynecological malignancy). A review of the literature was conducted. Results: Of the 471 patients who underwent RRSO, a total of 267 cytology samples were available for analysis. Four samples showed malignant cells, all four patients were diagnosed with ovarian and/or fallopian tube cancer at histologic examination. A fifth patient, of whom no cytology sample was obtained during RRSO, developed primary peritoneal cancer 80 months post RRSO. Conclusions: This study failed to show that cytology is of value during RRSO in detecting primary peritoneal cancer, however 36 % of patients with concomitant ovarian or fallopian tube cancer had positive cytology. Therefore, the routine sampling of peritoneal washings during RRSO is not found to be useful to detect subsequent PPC.