Abstract: The rapid growth of poultry industry has linked with increased output of keratin containing wastes. Keratinous wastes can be readily fermented to useful products and commodity chemicals by the appropriate microbes. The present research concerning biodegradation of keratinous wastes. From 82 fungal isolates, 27 isolates have keratinolytic activity. Identification tests indicated that the potent isolates were Alternaria tenuissima K2 and Aspergillus nidulans K7. Using chicken feather powder as a sole source of carbon and nitrogen, keratinase productivity were 53.4 and 55.8 U mL-1 by Alt. tenuissima K2 and A. nidulans K7 at the 6th and 5th day of incubation, respectively. Using additional carbon and nitrogen sources were not found to promote keratinase productivity, except when using starch and maltose. pH 7.5, 35°C and 7.5% inoculum ratio were the best for both keratinase production and feather solubilization by both fungi. Among different keratin containing wastes, chicken, duck and goose feathers were the most degradable keratinous wastes by Alt. tenuissima K2 and A. nidulans K7. During the course of investigation, keratinase production and degradation of keratinous wastes were positively and significantly correlated. Incubation of the produced keratinases at the optimum pH (8.5) and temperature (40°C) with different keratinous wastes led to about 70% hydrolysis of chicken, duck, goose and turkey feathers after 24 h of incubation. Goat hair, sheep wool and buffalo horn showed lower response towards keratinolytic hydrolysis. Therefore, keratinous wastes can be biologically degraded by either isolated fungi or their keratinases into useful products.