Potato (Solanum tuberosum L.) is the third most important agricultural crop in the world. Numerous factors influence its quality and yield, with viruses being one of the most significant. It has been shown that viral infections can lead to yield losses of up to 50% or more. Traditional Croatian cultivars such as 'Plitvički,' 'Lipice žuti,' 'Poli,' and 'Križpolje' play a crucial role in preserving biodiversity and serve as a source of genes for future breeding programs. To ensure their continued use, preservation, and the utilization of their full genetic potential, these cultivars need to be rid of viruses. In this study, the researchers eliminated Potato Virus M (PVM) and Potato Virus S (PVS) from four traditional potato cultivars: 'Plitvički,' 'Lipice žuti,' 'Poli,' and 'Križpolje.' Twenty shoot segments with nodes were taken from each cultivar and placed in 20 test tubes containing MS medium without growth regulators. When the explants grew into shoots, the shoots were cut into nodal segments without leaves, and five of these segments were placed in Magenta containers. Four subcultures were carried out. Three different virus elimination treatments were applied: ribavirin chemotherapy (RIB), followed by electrotherapy and then ribavirin chemotherapy (ET + RIB), and thermotherapy followed by ribavirin chemotherapy (37 °C + RIB). In the ribavirin therapy, shoots aged 40 days were used to isolate vegetative tips from axillary buds, which were then placed on MS medium with growth regulators and ribavirin. The cultivation period lasted for 95 days with one subculture. In the second treatment, ET + RIB, shoots were first subjected to a 15-minute treatment with a current intensity of 7 mA, after which vegetative tips were isolated and placed on MS medium with ribavirin for 95 days. In the 37 °C + RIB treatment, shoots were initially kept at a temperature of 30 °C day/28 °C night for 6 days and then raised to 37 °C day/32 °C night, where they were cultivated for 34 days. Afterward, vegetative tips (0.5 mm) were isolated and placed on medium with ribavirin (50 mg/l). ELISA showed that all three treatments were successful in eliminating Potato M and S viruses. The 37 °C + RIB treatment achieved the highest percentage of plants free from Potato M Virus (95.4%) and Potato S Virus (86.1%). The least successful elimination treatment was ET + RIB, with 82.6% of PVM-negative and 75.6% of PVS-negative plants. The highest percentage of virus elimination for both viruses was achieved in the 'Lipice žuti' cultivar, reaching 92.2%. 'Poli' had the lowest percentage of plants free from Potato M Virus (87.5%), while for Potato S Virus elimination, 'Plitvički' had the lowest success rate, with 64.6% of plants recovered.