Genetic variation among four mutants with parent of black gram (high seed protein, tall, bushy, and dwarf mutants) was investigated. The mutants were generated with physical gamma rays and chemical ethyl methane sulphonate. These mutants had some advantages like high protein content, lodging resistance, and high seed yield compared with parent cultivars (cvs.). The objective of the present investigation is to find genetic variation in mutants of black gram with their parents. The genetic variation was evaluated with 20 random primers, generated total 202 fragments scored with 58 polymorphic alleles, and the average was 10.1 alleles per locus and a range of 1–9 alleles. The average polymorphic rates were 38.37 among the mutants and parents through the 20 primers. Primers OPA-14 and OPI-04 revealed 35% of DNA polymorphism in this investigation. The genetic distance (GD) among the genotypes was 0.19 suggesting a significant degree of genetic diversity. The five genotypes were used to construct a dendrogram based on the similarity matrix, revealing a genetic distance varying from 0.600 to 0.725. This variation was due to the mutation induced by gamma rays and ethyl methane sulphonate. Further research is needed to analyze the sequence and expression of these mutated genes and to develop and improve black gram via genetic engineering to evaluate their use.