It is well documented that feed additives improve livestock productivity through improving feed intake, feed efficiency, and livestock health status. Oligosaccharide is categorized as a prebiotic additive that can modify the microbial ecosystem in the small intestine by creating an environment that is more favorable for nonpathogenic bacteria’s growth. Current research investigates the effects of chitosan-oligosaccharide (COS) from snail shells in the diet on quail performance and carcass characteristics. A total of 100 female DOQ were placed in a Completely Randomized Design, five treatments and four replicates with five birds for each replicate and were kept under standard management conditions for six weeks. Basal diet consisted of corn, rice bran, soybean, fish meal, coconut oil, minerals, methionine, and lysine, and was mixed in such a way to achieve 22% protein. Treatments were the basal diet without feed additive (T1) as the negative control, the basal diet with 28 ppm preparation of lactate acid bacteria, LAB (T2) as the positive control, the basal diet with 200 ppm of COS (T3), the basal diet with 400 ppm of COS (T4), and the basal diet with 600 ppm of COS (T5). The birds were having free access to the diets and drinking water. Bird’s weight and feed intake were recorded weekly. At the end of the experiment, two birds from each cage were selected and slaughtered for carcass assessment and weight digestive organ. The variables are feed intake, live weight gain, feed conversion ratio, carcass yield, breast meat weight, and organ weight. The data were analyzed by using Anova and comparison tests using the Duncan test. The results revealed that the addition of COS in the diet significantly reduced (P<0.05) feed intake, carcass yield, and dressing percentage and improved (P<0.05) feed conversion ratio, liver, and two ceca (P<0.05). Other parameters were not different (P>0.05) between treatments. Therefore, it could be concluded that the inclusion of chitosan-oligosaccharide (COS) in the diet improved quail performance by enhancing feed efficiency.