Chronic beryllium disease (CBD) is associated with the allelic substitution of a Glu 69 in the HLA-DPB1 gene. Although up to 97% of CBD patients may have the Glu 69 marker, about 30–45% of beryllium-exposed, unaffected individuals carry the same marker. Because CBD occurs in only 1–6% of exposed workers, the presence of Glu 69 does not appear to be the sole genetic factor underlying the disease development. Using two rounds of direct automated DNA sequencing to precisely assign HLA-DPB1 haplotypes, we have discovered highly significant Glu 69-containing allele frequency differences between the CBD patients and a beryllium-exposed, nondiseased control group. Individuals with DPB1 Glu 69 in both alleles were almost exclusively found in the CBD group (6/20) vs the control group (1/75). Whereas most Glu 69 carriers from the control group had a DPB1 allele* 0201 (68%), most Glu 69 carriers from the CBD group had a non-* 0201 DPB1 Glu 69-carrying allele (84%). The DPB1 allele* 0201 was almost exclusively (29/30) associated with DPA1* 01 alleles, while the non-* 0201 Glu 69-containing DPB1 alleles were closely associated with DPA1* 02 alleles (26/29). Relatively rare Glu 69-containing alleles* 1701,* 0901, and* 1001 had extremely high frequencies in the CBD group (50%), as compared with the control group (6.7%). Therefore, the most common Glu 69-containing DPB1 allele,* 0201, does not seem to be a major disease allele. The results suggest that it is not the mere presence of Glu 69, per se, but specific Glu 69-containing alleles and their copy number (homozygous or heterozygous) that confer the greatest susceptibility to CBD in exposed individuals.