Introduction: Surgical scar endometrioma is defined as the presence of an endometrial tissue near or inside an abdominal surgical incision. This is a rare clinical event that can occur in women after gynecological or obstetric surgery, with a global prevalence estimated at 0.01%-1%. The most prevalent clinical feature includes a painful mass with a cyclic pain that exacerbates with menstruation. The aim of this work is to facilitate the identification and support the diagnosis of abdominal wall endometrioma associated with the cesarean section scar, with basis on a case study of a tumor in the cesarean surgical scar of a patient who also complains of dyspareunia and menorrhagia. Case report: A 43-year-old female patient, G4PC4A0, with a single, rounded and painful subcutaneous nodule in the right inguinal region, on the cesarean section scar, which had progressively grown for two years. Patient also reported increased nodule size during menstrual period, associated with pain and menorrhagia. In February 2016, a surgical procedure was performed and by the post-surgical evaluation, the patient had already presented a menstrual cycle and reported decrease in symptoms. Biopsy report brought findings compatible with endometriosis. Conclusion: According to the literature, the clinical picture of the patient confirms the suspected endometrioma. The set of signals and symptoms associated with well-specified additional tests allowed an early and efficient diagnosis. The knowledge of the disease and the adoption of these criteria may mean a reduced burden on health services, but mainly, improve the quality of life of patients.