Saliva plays important roles in facilitation of a bloodmeal, lubrication of mouthparts, and parasite transmission for some vector insects. Salivary composition changes during the lifetime of an insect, and differences in the salivary proÞle may inßuence its functions. In this report, the amount and proÞle of salivary gland protein of the American visceral leishmaniasis vector Lutzomyia longipalpis (Lutz & Neiva, 1912) were analyzed at different times of insect development and diet. Protein content from unfed female sand ßies increased signiÞcantly with age, and a signiÞcant difference was observed in sugar-fed females during the Þrst 10 d of adult life. Salivary protein content sharply decreased 1 d after blood feeding, with gradual increase in concentration the following days. SDSpolyacrylamide gel electrophoresis analysis revealed that most polypeptides present in the saliva of sugar-fed also were present in the saliva of blood-fed females. Understanding changes in sand ßyÕs saliva contents at distinct days after emergence and the inßuence of a bloodmeal in this aspect may reveal the role played by saliva during leishmaniasis transmission.