BACKGROUND Sister Mary Joseph's nodule (SMJN) is rare and may occur independently or simultaneously with malignant tumors in the abdominal cavity. It has a poor prognosis. Endometrial carcinoma is the most common malignant tumor in the upper segment of the female reproductive tract; however, it rarely occurs with SMJN. We here report a case of endometrial carcinoma with SMJN. CASE SUMMARY A 75-year-old woman was diagnosed with endometrial cancer > 2 years ago. After multiple cycles of chemotherapy, an obvious but painless umbilical mass was detected 2 wk before admission. The patient did not undergo surgical treatment but received chemotherapy, which was different from previous chemotherapy, for three consecutive cycles after discovery of umbilical metastases. Currently, the umbilical metastatic tumor has reduced, and the quality of life of the patient has significantly improved. CONCLUSION Once the umbilical mass is found, the possibility of SMJN should be considered. We should also take into account the poor prognosis of endometrial carcinoma complicated with umbilical metastasis, especially in patients with advanced tumors, and it is important to choose an appropriate treatment.