Leprosy is a chronic disease which is caused by the infection of Mycobacterium leprae bacterium and leads to neurological consequences. Regardless of its slow progressiveness, it is an exceptionally serious disease that is continuing to be a challenging health problem around the world. Early diagnosis and treatment is much important in controlling Leprosy. Already published articles and books on Leprosy have been studied and summarized in this review to present a basic understanding on pathogenesis, symptoms, diagnosis and treatment of Leprosy.