Potato buds cvs. Spunta and Valor were cultured in vitro on MS solid medium supplemented with 0.2 mg ^-1 BAP. The resulting plantlets were irradiated with gamma radiation doses 10, 20, 30 and 40Gy. Irradiated single node pieces were transferred onto fresh MS with BAP. Plantlets survival percentage calculated after eight weeks, gamma radiation caused decrease in the survival percentage of micropropagated buds in both Spunta and Valor cultivars ranging from 91.4 % to 28.5% in cv. Spunta and 93.3% to 30.47% in cv. Valor, comparing with the values of the two non-irradiated cultivares 95.2% and 96.2% respectively. Microtubers produced from irradiated plantlets were decreased with increasing gamma radiation doses with changes in size and numbers. The estimated proline content in irradiated plantlets was increased with increasing gamma radiation dose. The genomic DNA of non-irradiated (control) in two cultivars and eight radiation treatments was amplified with 10 RAPD primers that generated 54 polymorphic bands. The highest number of genetic similarity was 0.9672 showed between irradiated plantlets with dose 20 and 30Gy in cv. Valor. However, the highest genetic distance was 0.3995 observed between irradiated plantlets with dose 20Gy in cv. Valor and 30Gy in cv. Spunta. The dendrogram generated by cluster analysis distinguished the irradiated plantlets genetically.