Leishmania survival and pathogenicity depends on the parasite’s capacity to adapt to different host environments through stage differentiation of promastigotes within the sand fly, and of amastigotes inside mammalian host cells. Leishmania stage-specific expression occurs in the absence of classical transcriptional regulation, raising the question on alternative regulatory mechanisms. We investigated the role of protein turnover by applying label-free quantitative proteomic on both L. donovani amastigotes purified from the spleen of infected hamsters and the derived promastigotes in presence or absence of the irreversible, proteasomal inhibitor lactacystin. Proteins were prepared from four replicates for each condition.