Disappearance of chlorothalonil, dichlofluanid, vinclozolin and carbendazim, as active ingredients of agrochemicals commonly used for the protection of greenhouse vegetables against fungal diseases, was studied comparatively. It was found that initial residues of chlorothalonil and dichlofluanid dropped by halfwithin 4 and 2 weeks after treatment, respectively, while the deposits of vinclozolin and carbendazim were the most persistent and after 5 weeks still constituted 50% of their initial levels. Therefore, the obtained results indicated that iprodione, procymidone and vinclozolin should ensure the longest effective protection of greenhouse tomatoes while chlorothalonil, and especially dichlofluanid, for the shortest.