A double-blind randomized study was performed to compare ionization with diclofenac sodium (150 mg) and ionization with saline solution in two groups of patients with scapulo-humeral periarthritis or elbow epicondylitis. The subjects of both groups were treated with 20 ionization sessions each lasting 30 minutes during a 1-month period. There was a significantly greater improvement in pain at rest, pain on pressure, pain on movement and joint swelling in the eleven patients treated with diclofenac compared with the thirteen placebo-treated patients, but no significant differences between the two treatments as regards functional impairment. However, placebo treatment produced a slight but significant improvement in pain on pressure, pain on movement and functional impairment. Further studies are needed to assess the relative role of the current and of autosuggestion in saline ionization response since both have well-known therapeutic effects on chronic rheumatic pain.