To assess the association between HLA-DRB1 alleles and shoulder destruction due to rheumatoid arthritis (RA) in Japanese, we typed for HLA-DRB1 alleles in 100 Japanese RA patients who could be classified into 5 groups: non-progressive (N) with normal radiographs; erosive (E) showing marginal erosion but no collapse; collapse (C) showing subchondral cysts followed by collapse; arthrosis-like (A) showing osteoarthrotic features; and the mutilating (M) showing mutilating bone destruction. The HLA-DRB1*0405 antigen frequency in N, E, C, A, and M types was 55%, 61%, 33%, 71%, 100%, respectively. That in the M type (100%) was significantly higher than that in the others (the N, E, C, and A types; 57%). These findings suggest that the most severe shoulder joint destruction pattern in RA, the M type, is associated with HLA-DRB1*0405.