In this study, Gas chromatographic/mass spectrometric study indicated that carbazole (CARB) is formed in oxygen free ɤ- irradiation of aniline / chlorobenzene mixtures. It seems that ɤ-radiation induces the formation of CARB in these mixtures via intramolecular dehydrocyclization of diphenylamine (DPA). The yield of CARB estimated via gas chromatography (GC), was found to be dependent on aniline – chlorobenzene molar ratio. Where, the maximum CARB yield was found at 1:1 molar ratio of aniline – chlorobenzene. At this reactants molar ratio, the effect of absorbed radiation dose and dose rate on the yield of carbazole was studied. The yield of CARB increases, linearly, as the absorbed dose is increased up to about 50 kGy. The G-value (5.8μM/J) of CARB was determined. It was found that, the yield of CARB increase as the absorbed dose rate increases (0.226 -0.904kGy/h). So, it can be concluded that CARB is formed, mainly, in the spurs. The mechanism of the CARB formation was discussed.