Background & objectives: Keonjhar district of Orissa State has been hyperendemic for falciparum malaria since many years with alarming deaths due to cerebral malaria, Therefore an entomological investigation to know more about the relative prevalence of Anopheles species was done. Methods: Daytime indoor resting and outdoor resting, light trap and double bed net collections were made. Surveys were also made to collect Anopheles immature in streams and paddy fields. The Anopheles mosquitoes obtained by different catching methods were identified and the known vector species were subjected to gut and salivary gland dissection for vector incrimination. The infected specimens of An. fluviatilis and An. minimus were subjected to polymerase chain reaction assay for identification of sibling species.