The study material consisted of K 1860 Septoria carvi isolate and single isolates of 18 other fungal species, chosen randomly from our own collection created during the studies of caraway diseases carried out in 2001-2006. Individual, general and summary biotic effects of the various fungi on Septoria carvi were determined by using the biotic series method and PDA (Difco) medium. Our results show that S. carvi is a weak competitor, because its growth was limited by all studied species of fungi representing the phyllosphere of caraway. Trichoderma, Gliocladium and Epicoccum purpurascens were recognized as positive and effective antagonistic fungi in relation to S. carvi. Moreover, the studied fungi that are pathogens of caraway and other plants, i.e. Fusarium spp., Rhizoctonia solani, Colletotrichum spp., Botrytis cinerea, Alternaria spp. and Phoma exigua proved strongly competitive to S. carvi, so these fungi could mask the symptoms of septoriosis at the first stage of the disease.