The purpose of this double-blind study was to evaluate the effects of iontophoresis with dexamethazone to iontophoresis with saline solution on patients who had acute (less than 3 months) pain from the Achilles tendon, in terms of range of motion, muscular endurance, pain and symptoms. Twenty-five patients (15 men and 10 women), aged between 18 and 76 years (mean=38), were evaluated before and after 2 weeks of treatment with iontophoresis, as well as after 6 weeks, 3 and 6 months and 1 year. Two groups were treated for 2 weeks with iontophoresis for each treatment. Three ml of dexamethazone were used for the experiment group (n=14) and 3 ml of saline solution for the control group (n=11). Both groups then followed the same rehabilitation programme for 10 weeks. Good reliability was found for the toe-raise and range of motion tests. Poor reliability was, however, found for the pain on palpation test, which was therefore excluded. No difference was found between or within groups for the toe-raise test. Several significant improvements were seen in the experiment group but not in the control group, in the range of motion test, pain during and after physical activity, pain during walking and walking up and down stairs, morning stiffness and tendon swelling. Even though the small sample size limits the possibilities to draw definite conclusions, we conclude from the present study, using a double-blind, randomised approach and a 1-year follow-up period, that positive effects from using iontophoresis with dexamethazone were found in the treatment of patients with acute Achilles tendon pain.