Sesame (Sesamum indicum L.) is an ancient oilseed crop with important agronomic, therapeutic, and industrial properties. However, in Morocco, the existing genetic diversity is quite limited. Thus, chemical mutagenesis, using ethyl methane sulfonate (EMS), was applied to induce novel genetic variability. Seeds of two sesame genotypes were treated using two EMS concentrations, 0.5% and 1%. The treated and untreated seeds (control) were planted according to a completely randomized design. Some mutant plants (M1) were identified and characterized for growth habit, root length, number of carpels per capsule, number of capsules per leaf axil, seed yield per plant, and seed color. Specifically, mutants with a tetra-carpellate capsule, three capsules per leaf axil, determinate growth, diverse seed colors, and a highly developed root system were found to be promising and useful for sesame breeding program aimed at developing productive and high-quality cultivars, particularly for stressful environments.