Five brinjal genotypes were chosen to study the effect of physical and chemical mutagens on the induction of variability. The physical mutagen gamma rays and chemical mutagens namely Ethyl Methane Sulphonate and Diethyl Sulphate were employed for treating the seeds to determine the LD50 values in brinjal. Germination percentage, shoot length and root length were measured under laboratory conditions. The mutagenic effect of gamma rays was found to be more effective than the chemical mutagens in seedling characters.