This study was carried out to determine potential effects of water deficit and nitrogen treatments on yield components of sorghum sudangrass and nutritional composition, fermentation, organic matter digestibility, gas-methane production of sorghum sudangrass silage. Plants were grown under combinations of three different irrigation levels (I100: 100, I75: 75 and I50: 50% of depleted water from field capacity) and three different nitrogen doses (N1: 100, N2: 200, N3: 300 kg ha−1). Experiments were conducted in randomized blocks - split plots design for two years in 2013 and 2014. Harvested plants were ensilaged, silage samples were opened after 60 days and relevant analyses were performed on silage samples. Irrigation treatments increased green herbage yield, yield components, acid detergent fiber (ADF), neutral detergent fiber (NDF), dry matter and crude ash and decreased crude protein, gas production and organic matter digestibility. Increasing nitrogen doses increased panicle and leaf ratio, crude protein ratio and green herbage yield and decreased dry matter and pH levels. The greatest ADF, NDF, metabolic energy, gas production and organic matter digestibility values were obtained from 200 kg ha -1treatment. Current findings revealed that increasing yield but decreasing quality values were observed with increasing irrigation levels. Appropriate nitrogen doses had positive impacts on green herbage yield and feed quality. There were not significant differences between N3 × I100 and N2 × I75 treatments. Therefore, a slight water deficit (I75) and normal nitrogen supply (200 kg ha−1) is recommended for sorghum sudangrass culture without any significant losses in yield and quality parameters.