Several genes controlling nodulation response in soybean, Glycine max (L.) Merr., have been found and their use in restricting nodulation with less desirable strains of Bradyrhizobium japonicum has been postulated. However, little is known of their linkage relationships with other genes. This report details genetic linkage tests of the Rj2 locus with 20 other loci: T, P1, L1, Y13, Adh1, W1, F, Rj1, Idh1, Fr1, Y9, Aco2, Dial, Fr2, Got, Mpi, Pgd1, Pgm1, Y10, and Y17. Only one of the genes tested showed evidence of genetic linkage with Rj2. The estimated distance of Aco2 from Rj2 was 44.7 +/- 2.1 genetic map units.