The study was conducted to investigate the effects of feed withdrawal on gastrointestinal weight, digestive condition, and carcass yield. The effects were studied in 36 HANWOO and 245 pigs. The weight of the gastrointestinal tract decreased with fasting time in both HANWOO and pigs. No significant differences in weight of HANWOO stomachs, intestinal tracts, and carcass yields were observed throughout the experimentals. Among pigs, significant differences in gastrointestinal tract weight were observed when comparing short fasting time (4 h) with long fasting time (above 12 h) (p<0.05). HANWOO and pigs showed no significant differences in carcass yield during fasting times. These results suggested that feed withdrawal for 16 and 12 hours is appropriate for HANWOO and pigs.