The potato cyst nematode Globodera rostochiensis and Globodera pallida are major economic and quarantine pest species of potato. First discovery of G. rostochiensis in Republic of Croatia was in the 2001 year in Međimurje county, and G. pallida in the 2002 year in Međimurje and Varaždinska county. The aim of this study was to determine the presence of the potato cyst nematodes on potato field where mercantile potato was cultivated for years, to determine population size and appropriate control measures. The dried soil samples were subjected to the process of separating cyst G. rostochiensis by flotation method in Spear flotation device and by morphological features. Intensity of infection was determined based on abundance cysts in 100 ml soil. The presence of G. rostochiensis was found in thirty analyzed soil samples. Number od cysts is univen, and average amount is 124/100 ml soil. It was determined vitality of cysts and number od eggs and larvea/g soil varies from 1.00 to 50.30. According to these data it was proven excess economic tresholds of 20 eggs and larvea/g soil. In order to stop population growth it is necessary to implement integrated potato protection, which includes the application of crop rotation, planting of resistant varieties of potatoes, if it is necessary the use of nematocides and regular monitoring and sampling of production areas.