Four Pleurotus spp. fungi (P. diamor, P. eryngii, P. sajor-caju, P. citrinopileatus) were compared for their potential to improve nutritional value of corn stover as ruminant feed. Corn stover was inoculated with the fungi under solid-state conditions and their results showed that P. sajor-caju and P. eryngii were better than the other two species of Pleurotus with respect to decreasing the acid detergent lignin (ADL) (8.99 vs 9.88 vs 10.16 vs 10.46). In contrast, P. eryngii had lower ability to degrade cellulose (13.38%). Corn stover treated with P. citrinopileatus had the highest crude protein (CP) content (7.65%), whereas treatment with P. sajor-caju resulted in the highest increase in essential amino acids (55.11%). Although fungal pre-treatment of lignocellulosic biomass does not always result in high-quality feed, overall, P. eryngii and P. sajor-caju improved the nutritive value of corn stover as a ruminant feed.