The present study showed the advantages of dried Bacillus subtilis culture (DBSC) supplementation on reducing ammonia gas release in the poultry house. In Experiment 1, 65-week-old Hyline W-36 hens were raised in individual wire-floor cages in a windowless house, and divided into two groups of 180 hens each. One group was fed diets without DBSC as the control and another group was fed a diet supplemented with 2% DBSC. In Experiment 2, 2-week-old broiler chicks were divided into 3 treatment groups of 20 chicks each and maintained in individual floor cages. One group was fed the diet without DBSC and other two groups were fed the diet supplemented with 1 or 2% DBSC, respectively. In Experiment 1, DBSC consistently reduced ammonia gas release in the laying house (p<0.01) and manure storage facilities (p<0.01). Incubation of feces for 1, 2, 3, 4, 5, 6, 24 or 48 hours showed that DBSC consistently reduced ammonia gas release. In Experiment 2, DBSC reduced ammonia gas release in the broiler house; however, DBSC had no effect on total N, urate-N and ammonia-N contents of feces, but it improved cumulative N utilization and decreased serum urea-N concentration when chicks were fed 1% DBSC.