In a family with a large pericentric inversion in one chromosome No. 6 (Inv(6)(p+q–)), HL-A was shown to have segregated with this chromosome in seven of seven cases. This raises the probability for the localization of HL-A to chromosome No. 6 from a prior 6 to 49 % and confirms the same assignment reported from cell hybridization work. The HL-A locus is most likely to be a little distal to the midpoint of either the short or the long arm of chromosome No. 6.