leishmaniasis is a public health and veterinary hazard. Screening of serum samples of 384 human and 387 domestic animals were carried out by indirect hemagglutination assay (IHAT) to detect antibodies against L. donovani and to see the involvement of animal reservoirs in Najran region, Saudi Arabia. The overall prevalence of human Leishmaniasis infection in Najran area, Saudi Arabia was 8.3%. The prevalence rate of human Leishmaniasis was significantly higher in summer (21.9 %) and spring (8.3%) than in winter and autumn. In addition, the prevalence rate of human Leishmaniasis was significantly higher in old age (8.8%) males were found to be infected with human Leishmaniasis, respectively. The highest titer in human was 1/256 with percentage of 43.8%. Antibody against L. donovani in domestic animals was detected and the overall proportion of occurrence was 1.6%. The prevalence rate of Leishmaniasis infection was significantly higher in goats than in sheep, camel and horses. The highest titer (1/512) was in goats. The study was thrown light on infected African and Asian workers as source of Leishmaniasis infection. Also, this study suggests the possibility of varied species of domestic animals to harbor the parasite and hence play a central role in the transmission. Consequently, this may hurdle our clarification of disease epidemiology.