An experiment was carried out to study the effect of six doses of gamma irradiation (0-350 kiloGray, kGy) on in vitro organic matter digestibility (IVOMD), digestible energy, gross energy (GE), total nitrogen (N), crude fibre (CF), neutral-detergent fibre (NDF), acid-detergent fibre (ADF) and acid-detergent lignin (ADL) of wood sawdust broiler litter. The results indicated that gamma irradiation increased the IVOMD and IVDE, except the dose of 50 kGy, and decreased the values of CF, NDF, ADF and ADL significantly (P<0.05). Digestible energy increased by 1030, 1040, 1330 and 1510 kJ/kg DM for 100, 50, 250 and 358 kCy, respectively, compared with the control. The dose of 350 kGy had the highest effect, resulting in reductions of 33% in both CF and ADL, 30% in NDF and 24% in ADF. There was no significant (P > 0.05) effect of irradiation on GE and N.