The diagnosis of Behçet’s disease (BD) relies on a thorough examination of clinical features and patient history, given the absence of specific laboratory tests. The broad spectrum of manifestations, variable onset intervals, and the disease’s course marked by remissions and exacerbations present challenges in its diagnosis. Over the years, more than ten diagnostic criteria have been developed to bring objectivity to the diagnostic process. The International Study Group Criteria for Behçet’s Disease, International Criteria for Behçet’s disease, and the criteria established by the Japanese Research Committee, commonly utilized in Far East countries, are the most frequently employed sets of criteria. In 2016, a new consensus classification for pediatric BD (PEDBD) was proposed. Nevertheless, it is crucial to recognize that the varied clinical spectrum may lead to certain patients not meeting the criteria, regardless of which criteria set is employed. Recurrent oral aphthous ulcers are the initial manifestation of the disease in most of patients with BD. It is essential to note that other mucocutaneous manifestations or even major organ involvements may also be the initial presenting symptom. Recent efforts have focused on developing diagnostic algorithms for early identification of ocular, neurologic, and gastrointestinal involvement of BD. These organ-specific diagnostic approaches can be particularly helpful, especially in the early stages when patients may exhibit only a few manifestations. Until specific features or laboratory tests are identified, the experience and judgment of the physician remain crucial and the most important factor in diagnosing BD.