The debilitating disease kala-azar or visceral leishmaniasis (VL) is caused by the kinetoplastid protozoan parasite Leishmania donovani. The parasite is transmitted by the hematophagous sandfly vector of the genus Phlebotomus in the old world and Lutzomyia in the new world. The predominant Phlebotomine species associated with transmission of kala-azar are Phlebotomus papatasi and Phlebotomus argentipes. The infected female sandfly transmits the parasite when it takes a blood meal. Understanding the molecular interaction of the sand fly-Leishmania during the development of parasite within the gut of the sandfly is crucial to understanding parasite life cycle. The complete genome sequences of sandfly vectors (Phlebotomus and Lutzomyia) are currently not available and sequencing efforts are underway. Non-availability of genome sequence can hamper identification of proteins in the sandfly vector. In the present study we have carried out proteogenomic analysis of unsequenced sandfly vector P. paptasi cell line using high-resolution mass spectrometry and comparative homology-based searches using related dipteran protein data (mosquitoes and fruit fly). This study resulted in identification of 1,312 proteins from P. papatasi based on homology. Our study demonstrates the power of proteogenomic approaches in mapping the proteomes of unsequenced organisms.