A total of 31 S-alleles was found in a survey of 197 cabbage plants representing 11 cultivars of diverse type. Most of these S-alleles also occurred in either kale or Brussels sprouts, but five of them have not been found previously and apparently occur only in cabbage. A more detailed study of five cultivars of spring cabbage showed only 12 S-alleles in all, with 6–10 S-alleles in four older cultivars and only 3 S-alleles in the newer more highly selected cultivar. S2 was by far the commonest S-allele, as it is in B. oleracea as a whole. The highly recessive alleles S5 and S15 were not particularly common in cabbage and this may partly explain why the sib problem in F1 hybrids is apparently less in cabbage than in Brussels sprouts. Three cases were found in which an S-allele was completely recessive in both the stigma and the pollen. The problems for the breeder created by this rather unusual situation are discussed.