The radiation degradation and decoloration of three textile dyes Janus Green B (JGB), Reactive Black 5 (RB5) and Apollofix Red (AR) have been studied as a function of gamma irradiation dose (0.1-8 kGy) and dose rate (0.5-4 kGy/ h). The starting G values for decolorations were found 0.3-1 molecule/100eV and the yields decreased with decoloration. The dose necessary for complete decoloration detected in 50 ppm aqueous solution was similar to0.5kGy for RB5, 2 kGy for AR and 8 kGy for JGB in air. The effect of N-2, N2O on the degradation and decoloration process was also studied. (C) 2003 Published by Elsevier Science Ltd.