The effects of mutation induction through the use of a chemical mutagen as a method of improving few agronomic traits in sesame (Sesamum indicum L.) were investigated. Healthy and dry seeds of sesame varieties (Abasena and Kelafo 74) were treated with hydroxylamine hydrochloride (HA) at six different concentrations (0.01, 0.02, 0.03, 0.04, 0.05 % (w/v) and control) with the aim of improving the growth and yield parameters of the plant. Bioassay studies showed highly significant difference in germination percentage of the two varieties under the treatment of the mutagen compared to the control. The results obtained from the quantitative parameters also revealed highly significant increase (P=0.01) in the plant heights, number of seeds/pod, number of capsules/plant, internode length and capsule length with decrease in the concentration of the mutagen. In addition, days to maturity have shown a negative mean shift in all the treatments and days to flowering showed a significant positive mean shift only at 0.02% concentration of HA. The chemical mutagen was therefore found to improve the quantitative traits associated with growth and yield of sesame. The induced variation can be exploited in the evolution of new varieties of sesame with improved agronomic traits.