Significant differences in a mutant form of Polish grass-pea obtained from parental cultivars Derek and Krab by chemomutagenesis were shown. Agricultural properties of plants (plant height, number of branches, number of pods per plant and their length and width, as well as number and weight of seeds per pod and maturity), geometrical features of mature seeds, and their microstructure were investigated. It was shown that the range of traits for the analysed features of mutants exceeded the variation observed for the original cultivars - Krab and Derek. This is especially visible for such yield structure traits as pod number per plant, seed number and weight per pod. From the agricultural point of view, very promising are mutants with reduced plant height and biomass, decreased number of lateral branches, improved lodging resistance and earliness. Analyses of technological usability factors (harvesting, drying, storage) involved assays of seed coat thickness and cotyledone cell microstructure. The obtained results are of key importance to the selection of the most promising material for further genetic trials and breeding practice.