Gamma ray induced 1076 mutants of sesame (Sesamum indicum L.) in M3 and M4 generations were evaluated for resistance to Fusarium wilt in a naturally infected field in Antalya. Sixteen mutant lines in the nursery were found to be promising as a source of resistance to Fusarium oxysporum f. sp. sesami. Subsequently, these lines and four local checks were screened in a randomised complete blocks design with three replications under naturally infected field conditions according to 1-9 visual field scoring scale in the 1998 and 1999 seasons. Based on the visual scorings, three mutant lines were identified for resistance to F. oxysporum f. sp. sesami. Pot screening procedure was also followed in order to verify the field results. Sixteen mutant lines and four checks were also tested for resistance to Fusarium wilt in pot culture inoculations in a growth chamber at 22°C and 16 hours day length. Based on the pot screening procedure, resistance to F. oxysporum f. sp. sesami was confirmed in the three mutant lines as recorded in the field.