Background: Human lungs have two fissures, namely oblique fissure and horizontal fissure. These two fissures divide the right lung into superior, middle and inferior lobes, while the left lung is divided by oblique fissure into superior and inferior lobes. The fissures of lungs may be complete, incomplete or absent. Thus, they may vary in length and depth. The knowledge of variations of fissures is necessary during lobectomies, x–rays and CT–scans of lungs. Hence, the present work has been carried out to study the presence, completeness and morphological parameters [length and depth] of oblique and horizontal fissures of human lungs. Methods: The study was carried out in 92 adult human lungs [46 right and 46 left] in the Department of Anatomy, Gauhati Medical College and Hospital, Guwahati. The lungs were collected from the Department of Anatomy and Department of Forensic and State Medicine, Gauhati Medical College and Hospital, and preserved in 10% formalin. Then, the lungs were examined for variations of oblique and horizontal fissures, and the morphological parameters were measured. Results: In the present study, 45.65% lungs showed complete oblique fissure and 54.35% lungs showed incomplete oblique fissure. Also, 41.30% lungs had complete horizontal fissure, 52.17% lungs had incomplete horizontal fissure and 6.52% lungs had absent horizontal fissure. Conclusion: A detailed knowledge of variations of oblique and horizontal fissures is required for correct radiological diagnosis of lung pathologies and to prevent postoperative complication following lobectomies of lungs.