This study was undertaken to improve nutritional values and digestibility of water-hyacinth by solid-state fermentation with a white rot fungi, Pleurotus sajor-caju. At the end of 56 days fermentation of CaCO3 treated water-hyacinth, significant (p<0.05) changes of crude protein, lipid, carbohydrate, ash, lignin, cellulose, hemicellulose, cellulose-lignin ratio and reducing sugar contents were detected. Crude protein, ash, cellulose-lignin ratio and reducing sugar contents were increased by 685, 47, 106 and 680%, respectively. In contrary, crude fiber, lipid, carbohydrate, lignin, cellulose and hemicelluloses contents were decreased by 36.8, 72, 19, 72.33, 37.5 and 4.57%, respectively. Ascorbic acid and carotenoid were increased by 42.9 and 122.8%, respectively. At 49 days of fermentation, the crude water-hyacinth extract showed very high CMCase, avicelase and amylase, moderate cellobiase and very poor pectinase and xylanase activities. In-vitro dry matter digestibility was also increased by 76%. The study concluded with the finding that P. sajor-caju has the potential for efficient degradation of water-hyacinth to convert the lignocellulosic wastes into nutritionally improved animal feed.