BACKGROUND: Endometriotic foci can be rarely found on the surgical incision following caesarean delivery and on perineotomy site following vaginal delivery.CASE: A 33-year-old woman with a history of caesarian section five years prior was admitted to the present clinic due to right groin pain with increasing intensity during menstruation. Ultrasound revealed an endometrioma-like subcutaneous mass directly under the right edge of the Pfannenstiel scar. The mass (3.5 x 2.4 x 2 cm) was removed en bloc with ultrascissor.CONCLUSION: The prevailing argument supports that it is a complication caused by the iatrogenic dispersal of endometrial material. Symptoms onset vary from one to five years postoperatively and mainly include pain and enlargement of the mass during menstruation. Diagnosis may be demanding due to the atypical presentation of the disease. Symptoms exacerbate during menstruation in only 20% of all cases. Abdominal ultrasound is extremely useful for diagnosis. The treatment of choice is surgical excision.