One of the dangerous insect pests of Guilan tobacco culture is cutworm ( Agrotis segetum , A. ipsilon, A. nigrum ). The damage of this insect starts from seedbed, but the main damage is observed after transplanting. The most dangerous stage of this pest activity takes place at 45 DAT and the peak of the infection is from May 22 to June 12. In order to select the most effective insecticide to control this pest, the following treatments were compared in a randomized complete block design with four replications: 1) chlorpyrifos (granules 5%) 30 kg/ha; 2) carbaryl (DP 85%) 3 kg/ ha;. 3) monocrotophos (SL 40%) 2 L/ha; 4) thiodicarb (SG 80%) 1 kg/ha; 5) methamidophos (SL 50%) 1 L/ha; and 6) control without any insecticide. Soluble insecticides were sprayed on the plants after transplanting, and chlorpyrifos GR was distributed under the plants. The evaluation of the insect damage on plants was started after observation of the first damage and continued for one month. The results obtained showed that the best treatment was chlorpyrifos with the smallest mean of infected plants, then carbaryl and thiodicarb. These treatments were significantly different from other treatments at the 0,01 level. There was not significant difference between methamidophos or monocrotophos compared with the control.