This research was conducted to evaluate the nutritional value of vicia faba residues processed with some chemical compounds using in vitro and nylon bag techniques. Treatments included unprocessed vicia faba residues (control) and processed with water (2.5 lit/kg DM), calcium oxide (160 g/kg DM), hydrogen peroxide (57 ml/kg DM) and sodium hydroxide (50 g/kg DM). The chemical compositions of the samples were identified using the standard methods. Ruminal degradability trial was performed using the nylon bag technique. In vitro digestibility of samples was determined by the batch culture method. Processing was effective on the chemical composition of vicia faba residues. Except for water, the other treatments increased Ash and decreased organic matter (p=0.0001). Calcium oxide had the highest effect on the mentioned traits. Crude protein amount was decreased in all treatments (p=0.0001). The lowest amount was observed in calcium oxide and sodium hydroxide treatments. The amount of acid detergent fiber in calcium oxide and hydrogen peroxide treatments was higher than other treatments (p=0.0017). Except for calcium oxide and water, the other treatments increased effective rumen degradability of vicia faba residues at rumen outflow rates of 2, 5 and 8 percent/hour (p<0.0001). The hydrogen peroxide had the greatest effect on increase of effective rumen degradability. Sodium hydroxide treatment increased dry matter (p=0.0001) and organic matter (p= 0.0029) digestibility. Also, calcium oxide and hydrogen peroxide increased the efficiency of microbial yield (p=0.0016). Totally, the results of this research showed that the sodium hydroxide and hydrogen peroxide treatments had the greatest effect on improving the nutritional value of vicia faba residues.