Background: Rabies is an infectious and preventable viral disease of mammals. It is caused byrnseveral Lyssavirus species, a group of negative sense RNA viruses, and most often transmittedrnthrough the bite of a rabid animal, commonly dogs. Many diagnostic methods have been used torndetect rabies virus antigen. The preferred method for routine diagnosis of rabies in fresh orrnfrozen brain tissues is the fluorescent antibody test.rnObjective: The aim of this study was to evaluate fluorescent antibody test for rabies detection inrnfresh, frozen and formalin-fixed brain tissue specimens in EthiopiarnMethods: The study was carried out on rabies-suspected brains of animals which were collectedrnfrom March 2017 to July 2017 at Ethiopian Public Health Institute. The detection of rabiesrnantigen was done in brain impressions from three areas of the brain: hippocampus, cerebellum,rnand brain stem. One portion of each paired specimen was prepared for fresh, frozen and formalinrnfixed FAT. It was treated with globulin labeled with fluorescein isothiocyanate. Specificrnaggregates of rabies virus antigen was detected by their fluorescence using a reflected lightrn(incident light) fluorescence microscope.rnResults: The sensitivity of fixed brain tissue compared with fresh FAT was 96.9% andrnspecificity was 100%.Frozen specimen gave similar sensitivity and specificity with fresh FATrnwhich was 100%. The association between Formalin fixed tissue sample & Fresh tissue samplernwhen it is done using FAT had p -value 0.257, frozen tissue sample & Fresh tissue sample had prnvalue 1.00 and Formalin fixed tissue sample & frozen tissue sample had p value 0.257 with nornsignificant difference.rnConclusion: Rabies detection in animals can be accomplished from diagnosis of rabies fromrnfixed brain tissues which offers similar sensitivity as detection of rabies in impression smears.