We report here an accessory fissure in the right lung. Accessory fissures are described as clefts of various depths lined by two layers of visceral pleura. Anomalies of location of the lungs may be produced by the accessory fissures. In our case, an unusual accessory fissure in the right lung was found in a 50 years old male cadaver. The accessory fissure was located between the superior and basal segments of the lower lobe of the right lung. Its depth was around 3 cm as an average value. Its length was found to be 12 cm on the surface of the lung. In conclusion, a surgeon must always remember the anatomical variations of the location of the lungs especially in lobectomies and in segmental resection. From the radiological aspect, an accessory fissure is important in that it can be mistaken for lung pathologies.