Salt tolerant mutants of potato (Solanum tuberosum L. ‘Sponta') were obtained via gamma irradiation. bud explants of two strains of potato (Sponta and lady rosetta were treated with various dosages of gamma irradiation, and the clonal generations were developed. Selection of salt-tolerant mutants was accomplished by in vitro selection media containing 30, 60, 90 and 120 mM NaCl. Molecular-level differences between the control and mutant plants were elucidated using ISSR technique, and the polymorphism rate according to the selected primers was calculated as 89.66%. Genetic distances between the controls and mutants were also calculated, and related dendrograms were produced. On average the mutants were genetically 27.5% different from the control plants. The greatest difference encountered between the control and mutants was 47%, which was detected in mutant plants produced by 20 or 30 Gy gamma irradiation and regenerated in selection medium containing 100 mM NaCl.