ABSTRACT: The effects of genotype, root size, storage, and processing on the content of bioactive compounds in carrots were determined to investigate the possibilities for optimizing the health-promoting properties of this vegetable. The content of polyacetylenes (falcarinol, falcarindiol, falcarindiol-3-acetate), carotenoids (α-and β-carotene), and isocoumarin 6-methoxymellein (6-MM) varied significantly between 6 genotypes of the Nantes type. The content of falcarindiol, falcarindiol-3-acetate, and 6-MM was significantly higher in small (50- to 100-g root size) than in extra large root sizes (>250-g root size). Refrigerated storage of the roots for 4 mo at 1 °C before processing resulted in a significantly higher content of polyacetylenes and no differences in the content of carotenoids and 6-MM compared with frozen storage of processed carrots. The content of falcarinol increased and that of falcarindiol and falcarindiol-3-acetate decreased during steam blanching of the carrots before freezing. No changes were observed in the content of carotenoids and 6-MM.