The purpose of the present studies was to determine the antagonistic effect of bacteria Bacillus spp. and Pseudomonas spp. towards selected fungi from the soil environment of carrot. Oats (Avena sativa L.), tansy phacelia (Phacelia tanacetifolia Bentham) and vetch (Vicia satica L.) were used as cover crops in the cultivation of this plant. In the traditional cultivation of carrot the population of bacteria was the smallest, while after the application of oats it was the largest. Laboratory tests showed that cover crops promoted the development of antagonistic Bacillus spp. and Pseudomonas spp. Irrespective of the experimental treatment, those bacteria were the most effective in limiting the growth and development of Fusarium oxysporum and Thanatephorus cucumeris (syn. Rhizoctonia solani), while being less effective towards Altenaria dauci and Alternaria radicina, and the least towards Sclerotinia sclerotiorum. The best total antagonistic effect of Pseudomonas spp. and Bacillus spp. towards the tested fungi was found after using oats and vetch, while the worst – in the traditional cultivation of carrot.