SummaryThe results of the second International BoLA Workshop, held in Wageningen, Netherlands in July 1980, are reported. These results arise from a comparison of 362 alloantisera to bovine lymphocytes, originating from 9 laboratories. The an‐tisera were tested against a selected panel of 144 lymphocyte samples, originating from 7 laboratories. Some of the antisera and lymphocytes had also been tested during the First International BoLA Workshop in 1978.Ten of the eleven specificities defined at the first workshop were confirmed, and an additional six new specificities were designated. Two of the additional specificities are subgroups of the w6 specificity. The data from this workshop are consistent with the hypothesis that BoLA antigens are controlled by a series of codominant alleles at a single autosomal locu