In Brassica oleracea L., plant regeneration from protoplasts is genotype-dependent and colony formation can be obtained routinely. In order to identify genes for regenerability, we performed a genetic analysis of the characteristic in the F2 generation of a cross between two accessions selected for high and low regenerability. Regeneration frequencies were obtained from protoplast culture of 248 individual F2 plants after 5, 10, and 15 weeks of culture on regeneration medium. Broad-sense heritability estimate was 0.492 at the early stage and lower (0.046-0.149) at advanced stages. The frequency distribution observed during short-term culture can be explained by two independent loci with duplicate dominant genes controlling regeneration. In long-term culture, one additional dominant gene can confer regeneration; i.e., three independent loci are responsible for regenerability. The results suggest that selection for high regeneration response may be efficient at early stages because of the lower environmental influence on the characteristic, and because fewer genes are involved at this stage than at advanced stages. The control of regenerability by a few dominant genes facilitates incorporation of the trait into breeding material. Molecular markers linked to the genes may assist in the selection of genotypes with high regeneration percentage in the future.