Introduction: Gynecomastia is the benign proliferation of glandular tissue in the male breast. It is a known condition, which occur physiologically or pathologically. Objective: To discuss the pathophysiology, etiology, clinical evaluation, investigation and management plans of gynecomastia. Materials/methods: The current literature was reviewed through PubMed, Scopus, and electronic databases to identify the best available evidence. Conclusion: Gynecomastia is a condition in which the male breast is enlarged due to an increase in ductal tissue, stroma, or fat. It commonly occurs in adolescents, adults and old age. Gynecomastia is presented with medical conditions such as extreme obesity, hypogonadism, liver, and kidney failure, in addition to certain drugs intake. Clinical evaluation must contain diagnostic confirmation, search for an etiological factor and clas‌sify gynecomastia into severity grades to guide the treatment. The optimal results are mainly achieved by surgery. Good preoperative preparation leads to good cosmetic results with high patient satisfaction and low complication rates.