The objective of this study was to develop a direct immunohistochemical assay to detect TCoV antigens in formalin-fixed paraffin-embedded sections prepared from experimentally infected poults. The sections of ileo, ileo-cecal junction and ceca regions from intestine were prepared and submitted to two different primary antibodies, first the non-biotin labeled polyclonal antibody for the indirect method, and second the biotin-labeled polyclonal antibody, both raised against IBV by immunized specific pathogen free chickens. All sections were submitted to immufluorescent assay (IFA), a conventional method, and the results compared. The direct immunohistochemical technique showed a higher frequency of antigen in tissues, especially from the ileo-cecal junction with no difference between results obtained by the conventional method. Finally, the immunofluorescence and all modalities of molecular approaches have been played an important role to the diagnosis and prevention of TCoV infections, although to be precise on infectious disease diagnosis, it is necessary complementary techniques. Here, was standardized the biotin labeled polyclonal antibody as reliable tool to be used as an alternative detection of Turkey Coronavirus. © 2007 Science Publications.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)