Abstract: The involvement of secretary immunoglobulin system in the protection of mucous surfaces by locally produced antibodies lead to the demonstration of IgA. IgA in the intestine of immune birds may limit coccidian replication. Enzyme linked immunospot (ELISPOT) assay was employed to detect the mucosal immune response (IgA antibody secreting splenic cells) in chicken vaccinated with egg adapted gametocytes antigen. Twenty to twenty-five % (200,000 to 250,000/106 cells) of chicken splenic cells stimulated with gametocytes antigen were detected as IgA secretors. Results of the ELISPOT revealed that spleen is one of the major source of cells producing IgA in chickens. Such a high number of IgA antibody secreting cells indicate protection in birds vaccinated with gametocytes antigen via oral route against coccidiosis. ELISPOT assay is found to be an advantageous alternative to conventional haemolytic plaque technique, being simpler and of equivalent or even greater sensitivity.