Restriction fragment length polymorphism (RFLP) of the cartilage-specific type II collagen gene has been studied in the Finnish population. Two high-frequency alleles, also reported in other populations, were detected. The Hind lll allele had a frequency of 0.33, and that detected with Pvu II a frequency of 0.46. Both of these frequencies resembled the ones reported for other populations. Also one Bam HI allele, not earlier reported, was found at a low frequency. Two other previously reported polymorphisms for BamHI and EcoRI were not detected in the Finnish population. The RFLPs showed a fair agreement with the Hardy-Weinberg equilibrium. A linkage disequilibrium was found between PvuII and Hindlll markers. The α1(II) collagen gene seems to be more conserved in populations of various origins than the α2(I) collagen gene. These polymorphic collagen markers would be useful in linkage studies of various inherited cartilage disorder