Endometriosis is defined as the presence of endometrial tissue at the sites other than the uterine lining and responds to the cyclical ovarian hormonal activity. It is a multidimensional and a complex disease which has an impact on physical, mental, sexual, and social aspects of the life of a woman. Here is a case report of a patient, presented to the department with pain and swelling in her left side of the previous cesarean scar. It was surgically removed and was diagnosed to be an endometrioma of rectus sheath and rectus abdominis muscle on histopathology.