In this review recent advances made in the field of human leishmaniasis have been discussed with special emphasis on the parasite, and various serological and molecular methods of diagnosing the infection. The article also reviews various modes of parasite transmission including vector borne, blood transfusion, needle sharing, sexual and person-to-person. Microbiological methods including the bone marrow, spleen, liver, lymph node aspirations and various staining methods used to demonstrate the amastigotes of the parasites and various in vitro promastigote culture methods are discussed in detail with their comparative sensitivity rates.