Trypanosomosis adversely affects the health, productivity and working capacity of animals. Trypanosoma evansi, the causative agent of surra, is principally transmitted by hematophagous flies (Tabanus, Stomoxys, Chrysops, Haematopota, Lyperosia and Atylotus). A cross sectional study was carried out in three districts of the Cholistan desert, Rahimyar Khan, Bahawalpur and Bahawalnagar, to estimate the sero-prevalence of T.evansi amongst camels. From the 1,000 visited animals, 0.7% were positive in Giemsa stained thin smear and 48% were positive in ELISA/T.evansi. This study declares Cholistan desert to be a high risk area for T. evansi. Studies on trypanosomosis of various animal species (sheep, goat, horses, buffaloes, cattle and donkeys) are underway and various serological, hematological, biochemical, molecular and immunological parameters are being investigated. Tabanus striatus and Stomoxys Calcitrans have been identified as major vectors of surra at Cholistan Desert.