This paper is elaborated etiology of origin, diagnostic and treatment of diaphragmatic hernia. The paper is divided into several important units. At the very beginning, the functionality of diaphragm is described, as well as its embriological and anatomic features. In every chapter, etiology and diagnostic of every type of diaphragmatic hernia is analyzed, as well as the methods of their operational care. The third part of the paper in detail describes Morgagni's hernia, such as rare front retrosternal diaphragm defect. The explanations are its anatomic features, epidemiology, most common symptoms, and conditions that can further aggravate the symptoms. It is further spoken about diagnostic tests which are necessary to carry out, that way the diagnosis is corroborated, operative procedure and achieved results. In the fourth part, classification of hiatal hernia is shown, amd all four types of hernia are accurately described. The tests that are being performed are described, so diagnosis can be confirmed. At the very end of paper, the reader gets acquainted with certain principles of operational procedure, which are accepted among all experts of the area.