The incidence of endometriosis in post-operative abdominal scars is rare. We describe two cases of abdominal endometriosis diagnosed by fine needle aspiration (FNA). Both patients presented with subcutaneous masses at previous cesarean section scars with cyclic symptoms of pain. The cytologic smears were cellular and comprised two distinct cell populations consisting of epithelial and stromal components. An epithelial component consisted of flat sheets of polygonal cells and the second stromal component showed crowded clusters of spindle cells or isolated single cells. Hemosiderin-laden macrophages were found in the background. FNA offers a safe and effective tool for diagnosis of abdominal wall endometriosis.