BACKGROUND Fever is a common manifestation of an illness. Thrombocytopenia is the most frequent finding in febrile illness. Thrombocytopenia with fever narrows the differential diagnosis of clinical entity and help in reaching the diagnosis of febrile illness. The present study is carried out to find the cause of thrombocytopenia with fever and to assess the clinical complication associated with severity of thrombocytopenia and fever. MATERIALS AND METHODS This study was carried out in Department of General Medicine of Jhalawar Medical College, Jhalawar, Rajasthan during period of July 2016 to September 2017. Total 100 patients were enrolled in this study. Informed written consent was taken from patients. This is a hospital-based observational study. RESULTS Dengue was the most common cause of febrile thrombocytopenia (50%) followed by malaria (23%). The other causes were viral fever (19%), scrub typhus (4%), mixed dengue and scrub typhus (2%), and septicaemia (2%). The patients were in the age group 16 - 80 years with 60 male and 40 female. Maximum patients (76%) were found to have thrombocytopenia in range of 50,000 - 1,50,000/cumm, 16 cases had thrombocytopenia in the range of 20,000 - 50,000/cumm, while 8 cases had thrombocytopenia in the range of < 20,000 cumm. Bleeding manifestations were very rarely seen as present in 3 cases (3%) with petechiae as the commonest bleeding manifestation (2%). Severe thrombocytopenia was seen in dengue fever and falciparum malaria. Mortality was observed in 2 cases (2%) and multiorgan dysfunction was present in all those 2 cases. CONCLUSION Dengue is the commonest cause of febrile thrombocytopenia and severity of thrombocytopenia was not associated with increased mortality, but mortality was due to multiorgan dysfunction.