OBJECTIVE: The purpose of the study was to assess the feasibility of intraoperative sentinel node (SN) detection using injection of patent blue dye and radioactive tracer beneath the tumor of patients with endometrial carcinoma. METHODS: Hysteroscopy was used for injection of 2 ml of patent-V blue, followed by 20-50 MBq technetium-99 m-labelled nanocolloids into the subendometrial layer underlying the tumor of 60 patients with endometrial cancer. Then SN biopsy, pelvic and paraaortic lymphadenectomy, hysterectomy and bilateral salpingo-oophorectomy were carried out through laparotomy or laparoscopy. RESULTS: Sixty patients aged 43 years to 87 years (median age 65 years) were enrolled in this study. Sentinel nodes were identified in 49 of 60 patients (82%). The mean number of SN retrieved was 3.7 per patient (range, 1 to 8). Sixteen patients (33%) had SN in both pelvic and paraaortic areas. No patient had SN only at the paraaortic level. Metastatic disease was found in 9 patients (15%). In 8 of them at least one SN was positive. CONCLUSION: Intraoperative sentinel node detection is feasible in patients with endometrial carcinoma using hysteroscopy for injection of blue dye and technetium-99 m beneath the tumor. This technique may actually enhance the chances of detecting metastatic disease, while reducing the extent of the surgery.