Chrysanthemum is one of the most important ornamental plants growing under covers in Poland but it is often infected by soil fungi. Investigations were carried out in 1999-2001 (summer and autumn) in 9 horticultural farms in Sandomierz district. Plants with symptoms of stem and root rot, leaves yellows and wilt were noticed on the investigated plantations. The results of mycological analysis showed that chrysanthemum plants were colonized by Fusarium spp., Cylindrocarpon spp., Rhizoctonia spp., Sclerotinia spp. and Alternaria spp. Among isolated fungi Fusarium oxysporum, Fusarium avenaceum and Sclerotinia sclerotiorum were predominating pathogenic species. Cv. Snowdon was colonized by pathogens most frequently, while the population of pathogenic fungi from cv. Royalys was the lowest.