Hand radiograms of 119 consecutive patients affected with rheumatoid arthritis (RA) were examined. The patients were distributed in different groups: 46 with (RF+) and 73 without (RF-) rheumatoid factor; 23 with (ANA+) and 96 without (ANA-) antinuclear antibodies. We found that RF+ group significantly differs from the RF- in order to the presence of symmetrical erosions of proximal interphalangeal joints (PIP) and the presence of monolateral erosions of metacarpophalangeal joints (MCP), particularly of the 2nd. We also observed that the frequency of MCP erosions, particularly of the 2nd was higher in ANA+ than in ANA-, and that monolateral PIP erosions were higher in ANA- than in ANA+ group. Moreover, the patients having both RF and ANA more frequently show erosions of symmetrical PIP and monolateral MCP as well as monolateral of the carp. It is therefore suggested that in RA patients having RF or ANA the articular lesions of the hand are different from those of the patients who don't show such serological markers.