Presence of endometrial glands and stroma in places other than the uterus is called endometriosis. It can be pelvic or extra-pelvic. Abdominal scar endometriosis is an extra-pelvic endometriosis that can occur after surgery involving the uterus. Post-caesarean section, scar endometriosis is a rare event. The diagnosis is frequently made only after excision of disease tissue. We present a case of post-caesarean section abdominal scar endometriosis presenting as a tumor on the abdominal wall, which was diagnosed by fine needle aspiration cytology and confirmed by cell block preparation.