To evaluate, by means of a longitudinal study, radiographic involvement of metacarpophalangeal and radio-carpal joints in hand osteoarthritis, its relationship with erosive disease and its progression, 368 patients with hand osteoarthritis were enrolled. All patients underwent hand X-rays. On the basis of the presence of central erosions in interphalangeal joints, patients were divided into three groups: 0-no central erosions, 1-one joint with central erosion, and 2-two or more joints with central erosions. A longitudinal study on 44 patients and nine normal controls, whose X-rays were available after 3.9 years, was performed. The radiological involvement of metacarpophalangeal and radio-carpal joints was evaluated using Kellgren-Lawrence and OARSI scores. Low number of joints showed Kellgren-Lawrence values >= 2 group 0, 42/1290 (3.3%); group 1, 10/410 (2.4%); and group 2, 36/1980 (1.8%). Low score values were obtained for all radiographic items. Only metacarpophalangeal joint space narrowing score showed significant increase from groups 0 to 2. Subsequent adjustment for age, gender, and BMI did not confirm the statistical significance. Marginal erosions were rarely found (6.7% of joints). Metacarpophalangeal and radio-carpal radiographic per patient scores significantly worsened at follow-up, but no significant increase in joints with Kellgren-Lawrence score >= 2 was found. In normal controls, no significant radiographic worsening was found. Only a minority of metacarpophalangeal joints shows a Kellgren-Lawrence value ae2. Metacarpophalangeal and to lesser extent radiocarpal joints had significant worsening at follow-up. Metacarpophalangeal joint involvement in hand osteoarthritis is mild but progressive. Radiocarpal involvement is negligible.