Field trials were carried out in the course of 1995, 1996 and 1997 in the Experimental field of Tobacco Institute - Prilep, in order to determine the effects of some selective herbicides on the weed flora and tobacco plants. The following herbicides were investigated: Devrinol (50% napropamid) in a rate of 5.0 kg/ha, Galex (250 g/l metolachlor + 250 g/l metobromuron) 5.0 l/ha, Fusilade super (125 g/l fluazifop-p-butyl + 250 g/l solvent) 3.0 l/ha and Treflan (480 g/l trifluzalin) 1.0 l/ha. The design was randomized block in three replications. The chemicals Devrinol, Galex and Treflan were applied before tobacco transplanting, and Fusilade super after weed germination, i.e. 15 days after treatment. Untreated plots were used as a check. During the three-years investigation, all chemicals showed a positive effect in the control of the most frequently appearing weeds in the trial plots. The best effect in the weed control was obtained by application of Galex and Treflan. In the course of investigation, the appearance of weeds in relation to the control (100.00%) in the plots treated with Galex and Treflan ranged 5.92%-32.6% and 15.13%-36.8%, respectively. The corrected yield in the variants treated with these chemicals was increased for 13.8%-38.2% in relation to the control. The chemicals investigated did not show a relevant positive effect on the average yield of tobacco produced in treated plots.