Background: Endometrial cancer is the most common gynecological cancer in developed countries. Autoimmune thrombocytopenia is a rare cause of thrombocytopenia in solid tumors and to the best of our knowledge, this is the first case reported associated with clear cell endometrial cancer.Case report: A 52-year-old woman patient diagnosed with endometrial carcinoma and total abdominal hysterectomy and bilateral salpingo-oophorectomy has been performed. After three cycles of chemotherapy, patient developed grade IV thrombocytopenia, which lasted for one month despite chemotherapy interruption. Bone marrow biopsy and some other tests were performed and she was diagnosed to have autoimmune thrombocytopenia.Conclusion: Autoimmune thrombocytopenia is a diagnosis of exclusion. Immune-mediated paraneoplastic syndrome include autoimmune thrombocytopenia is well known in hematological cancers, but it is rare in solid tumors. New developments in the treatment of primary cancer by clarification of paraneoplastic syndromes immunology should be considered.