SUMMARYIn the large genetic survey ‘Provinces Françaises’ the recombination fractions in the HLA system have been estimated by a family analysis programme (FAP). A total of 1332 families were analysed and in general the findings were in agreement with recombination fractions reported previously. The maternal recombination rates were on average 1.8 times higher than the corresponding ones for males. The comparison of the recombination fractions with the corresponding physical distances suggests the existence of hot spots of recombination. The analysis did not show deviations from expected values for HLA‐A and B alleles on HLA‐A/B recombinant haplotypes. However, analysis of HLA‐B/DR recombinant haplotypes showed a skewed distribution of B and DR alleles. The significance of the findings is difficult to evaluate as all results are estimated numbers and frequencies but a manual analysis of the recombinant families confirmed the observations. HLA‐B/DR recombinant haplotypes carried oftenHLA‐DR3andDR11whereasDR2andDR7were more rarely present on recombinant haplotypes. DR4 had an increased incidence on BF/DR recombinant haplotypes but not on A/B or B/BF recombinant haplotypes. Some of the haplotypes with the strongest linkage disequilibria asA1, B8, DR3andA3, B7, DR2seem to be less frequently involved in recombinations than other haplotypes. Variations of recombination rates depending on certain alleles or haplotypes might partially explain the conservation of some haplotypes or part of haplotypes