The herbicide fluridone (1-methyl-3-phenyl-5-[3-trifluoromethyl(phenyl)]-4(1H)-pyridinone) affects processes related to plant growth and development. It interferes with carotenoid biosynthesis by inhibiting the activity of phytoene desaturase which converts phytoene to phytofluene. Besides, fluridone indirectly inhibits abscisic acid (ABA) biosynthesis. The aim of the present study was to examine the effect of fluridone on plant pigments and proanthocyanidins in Muscari armeniacum leaves and on the dormancy of inflorescence shoots. In carried out experiments, uncooled M. armeniacum bulbs with fully differentiated adventitious roots were used. Three-week soaking of bulbs in water solutions of fluridone at concentrations of 5 and 10 mg dm^-3 significantly inhibited root growth of M. armeniacum plants. Besides, fluridone caused degradation of chlorophylls and carotenoids in the primary leaves of this species. Leaves obtained from fluridone-treated bulbs showed a pink color due to the presence of anthocyanins, but histological analysis showed that these pigments were found only in the leaf parenchyma and not in the epidermis. Secondary leaves grew from bulbs after a long, 54-days, treatment with fluridone contained almost no carotenoids and chlorophylls. This longer treatment of M. armeniacum bulbs also resulted in a large increase in anthocyanin and proanthocyanidin contents. The high anthocyanin content in leaves is visible effect of fluridone-induced stress. Application of fluridone to M. armeniacum bulbs resulted also on breaking the dormancy of inflorescence shoots.