Present study investigated the histopathological changes in the spleen of albino rat (Rattus norvegicus) after chronic application of Metanil Yellow at a sublethal dose of 3 g/kg body weight for 30 and 45 days with daily diet. Histopathological changes in the spleen tissue were observed under light microscope after staining with Haematoxylin–Eosin. Studies revealed the degenerative changes in both the white and red pulp regions. Trabeculae and follicular regions were rarely damaged. But at 45 days exposure it was maximum showing distortion and degeneration in both the white pulp and red pulp regions, in particular.