A.C. Siyunda, N.M. Mwila, M. Mwala, K. Munyinda, K. Kamfwa, G. Chipabika Callosobruchus maculatus, infestation, mutants, parent material, postharvest 12-22 7 (1) 2023 January 2023 Research studies were conducted to evaluate the potential of mutation breeding as a modern tool in extending the shelf-life of cowpea that suffers heavy losses when attacked by Callosobruchus maculatus. The study was done under the no-choice infestation laboratory conditions. Significant variations were observed where mutants outperformed parental genotypes on average across all the parameters under consideration at a 5% level of significance. Mutants recorded on average 50.36 eggs laid/100 seeds compared to 115.86 eggs/100 seeds on parent material. Adult emergence of 48.08% was recorded in mutants compared to 81.31% on parent material. In terms of the developmental period, mutants recorded 25.42 days compared to 19.75 days in parental material. Significant variations were also observed in percent infestation as mutants recorded 32.18% compared to 54.05% in parent material on average. Mutants recorded 12.09% while parent material recorded 26.59% in terms of weight loss percent. On average, a growth index of 4.12 in parent material was also recorded compared to 1.99 in mutant lines. Therefore, a successful extension in the genotype shelf-life through mutation breeding was observed. The researcher recommends the inclusion of BBBT1-11(best performing mutant line across all parameters) in the cowpea breeding programs that have a focus on developing resistant cowpea varieties to address the losses experienced at postharvest in cowpea production, thus extending shelf-life in a more cost-effective, less time consuming and environment-friendly manner.