Introduction: Malaria, dengue, typhoid, scrub typhus and several viral infections have been classically responsible for outbreaks of acute febrile illness. In recent years, scrub typhus has rapidly remerged to become the major cause of AFI in many parts of India, especially during the monsoon and postmonsoon seasons. Scrub typhus, caused by Orientia (formerly Rickettsia) tsutsugamushi, is an acute infectious disease that is transmitted to humans by an arthropod vector of the Trombiculidae family. This study was carried out to know the epidemiology and seroprevalence of scrub typhus in patients of acute febrile illness as early diagnosis and institution of specific treatment will reduce morbidity and mortality. Material and method: This prospective, observational study was carried out at a tertiary care hospital in the Hadoti region of Rajasthan from August 2018 to December 2018. All demographic data and detailed history were recorded. Scrub typhus serology was tested for IgM antibodies against O. tsutsugamushi using IgM ELISA kits( INBIOS). Result: Total 609 samples were tested for scrub typhus out of which 120 samples were found positive. Out of 120 sample 62 and 58 were males and females respectively. Highest seropositivity was found in 21–40 year age group and among rural population. The clinical manifestations varied from minimal to severe illness with 3 case fatalities. Conclusion: Scrub typhus should be included in the differential diagnosis of acute febrile illness along with malaria and dengue fever which are other endemic diseases in this region, which will help in proper diagnosis, timely and adequate treatment.