In the study 9 varieties of winter rye: Bosmo, Dańkowskie Amber, Dańkowskie Diament, Dańkowskie Złote, Daran, Kier, Rostockie, Stanko, Walet and one summer and winter sown variety - Bojko cultivated in organic system were compared. The research was conducted in 2012-2013 in two different locations: Grabów (Masovian voivodeiship) and Taraskowo (Podlasie voivodeship). The number of weeds and their dry matter were analyzed in two growing stages of rye: tillering and dough stage. Moreover the analysis of height, number of tillers and yielding of rye varieties were done. In dough stage number of weeds was big, 235 pcs∙m-2 on average, but their dry matter was on the level of 55 g∙m-2 on average. Rye varieties did not differ significantly due to the number of weeds, based on means from 2 years and locations, except of Bojko. Different reactions of rye varieties in relation to weeds in locations were observed. The most competitive varieties according to dry matter of weeds in dough stage were in Grabów: Dańkowskie Złote, Daran and Walet, and in Taraskowo: Bosmo, Dańkowskie Diament and Rostockie. There were no significant correlations between the level of infestation and morphological features of rye varieties: height and tillering. The observed level of weed infestation did not significantly affect grain yield of tested rye varieties.