Forty-nine Israeli Jewish patients with rheumatoid arthritis (RA) were studied for their HLA, A, B, C, DR antigen frequency. A significant increase in HLA Aw31 and HLA DR1 was observed (p<5.10-3 respectively). 45% of Aw31 positive patients were seronegative for rheumatoid factor, while most HLA DR1 positive individuals were seropositive. DR5 was found to be significantly decreased (p<5.10-4). Contrary to previous reports, DRw4 was found to be within the range of antigen frequency of the controls (34.7% vs. 32%). It is suggested that in our population of patients Aw31 and DR1 and not DR4 are highly associated with adult onset of RA.