Sesame (Sesamum indicum L) is one of the major oil crops with potential for production by small- scale holders in the marginal agro-ecological zones of Kenya. Variability studies on yield and yield components of sesame mutant lines now in M7generation was carried out in two locations for two seasons in Kenya. The objective of
the study was to assess performance of the mutant lines developed through induced mutational breeding. According to mean performance, the thirty selected mutant lines and four check cultivars showed a wide range of genotypic variability for all the studied traits. Seed yield per plant registered the highest coefficient of correlation (63.8%). In addition, seed yield had positive and significant (P