The effects of herbicides nicosulfuron, rimsulfuron and prosulfuron+primsulfuronmethyl on eight populations of Sorghum halepense L. (Pers.) under controlled conditions were investigated. The herbicides were applied at different rates (0x; 0,5x; 1x; 1,5x; 2x; 3x recommended application rate for field use) when plants reached the height of 20-25 cm. The parameters measured seven days after treatment were leaf surface and fresh and dry mass of plants; the obtained results were then used for ED50 calculations. The response of Sorghum halepense populations to nicosulfuron, rimsulfuron and prosulfuron+primsulfuron-methyl varied from population to population, and depending on the applied rate and the measured parameter. Resistance development was not observed in any of the populations that survived herbicide treatment before seed collecting. Only the population P2 showed somewhat decreased susceptibility to nicosulfuron, which can be regarded as an early stage of resistance development.