The aim of this research was to evaluate the effects of feeding fermented sago waste on production performance and nutrient digesbility of male kacang goats. The study employed a randomized block design, with 4 dietary treatments, i.e, of Field Grass (FG), Fermented Sago Waste (FSW) and Concentrate. The treatments were: T0 = 60% FG + 0% FSW + concentrate, T1 = 45% FG + 15% FSW + concentrate, T2 = 30% FG + 30% FSW + concentrate, and T3 = 15% FG + 45% FSW + concentrate. Each treatment consisted of three groups, so that the number of experimental units were 12 kacang goats which were grouped according to body weight between 18-23 kg. The results showed that dietary inclusion of FSW to substitute FG increased (P<0.05) feed intake, ADG, feed efficiency, dry matter digestibility (DMD) and organic matter digestibility (OMD) of kacang goats. However, the inclusion at T1 and T2 decreased (P<0.05) the R/C ratio in comparison to control group. The T3 treatment produced the highest ADG, DMD and OMD values. In conclusion, FSW is able to replace FG and therefore potential to be used as a forage source for ruminants in West Kalimantan.