Mesothelial cyst of the round ligament is a rare finding in females, with only a few cases reported so far. A case of a 25 year old female patient presenting with a palpable mass in her right inguinal region is presented. The preoperative investigation through ultrasound (U/S), computed tomography (CT) and magnetic resonance imaging (MRI) revealed the presence of an intraabdominal cystic lobular mass in the inguinal canal, in contact with the femoral vessels. The mass was excised and the diagnosis of a benign mesothelial cyst was made through pathological examination. Even though it is a rare condition, it is advisable that clinicians consider in the differential diagnosis when evaluating a non-reducible mass in the inguinal region of a female patient.