The effects of different levels of micronized insoluble fiber (MIF) on broiler performance and litter moisture were assessed in 320 one-day-old male broilers (Ross 308). Feed was supplemented with 0, 0.3, 0.4, or 0.5% MIF during both the starter (1 to 14 d) and grower (15 to 42 d) periods. Supplementation of MIF was associated with dose dependent increases in daily BW gain and feed conversion ratio throughout the experimental period (P < 0.01), whereas feed intake was not influenced by MIF concentration. As MIF content increased, the relative weight of digestive organs was not changed (P > 0.05). Supplementation of MIF resulted in dose dependent increases in the ileal villus height:crypt depth ratio and number of goblet cells (P < 0.05), and a dose dependent decrease in litter moisture beginning during the third week (P < 0.01). These findings indicate that inclusion of 0.5% MIF in feed resulted in the greatest improvements in broiler performance, intestinal morphology, and litter moisture.