In a pilot study 38 patients with lateral humeral epicondylalgia were randomly allocated to two treatment groups. Group S (stretching) was treated with a contract-relax-stretching program while group E (eccentric exercise) underwent an eccentric exercise program. Both groups also received forearm bands and wrist support nightly. The programs were carried out daily at home during 12 weeks. Evaluation before and 3, 6 and 12 months after treatment, included subjective assessment of symptoms using visual analogue scales and grip strength measurements. Thirty-five patients were available for follow-up. Five patients, three in group S and two in group E, did not complete the programs due to increased pain while 30 (86%) reported complete recovery or improvement. Reduced pain and increased grip strength were seen in both treatment groups but 12 out of 17 patients (71%) in group E rated themselves as completely recovered as compared to 7 out of 18 (39%) in group S (P=0.09), and in group E the increase in grip strength after 6 months was statistically significantly larger than in group S. In a second study the eccentric training regime was used in a consecutive series of 129 patients with lateral epicondylalgia. The patients were divided into two groups with one group consisting of patients with less than one year duration of symptoms and the other comprised patients with a duration of symptoms for more than one year. The results of treatment were evaluated in the same way as in the pilot study, and also after 3.4 years using the scoring system by Verhaar et al. At the end of the treatment period statistically significant improvements were seen in all VAS recordings and in grip strength. After 3.4 years 38% had excellent, 28% good, 25% fair and 9% poor results according to the score. In the self-rated outcome 54% regarded themselves as completely recovered, 43% improved, 2% unchanged and 2% worse. No significant differences were seen between patients with a duration of symptoms for more than one year compared to patients with symptoms for less than one year. The eccentric training regime can considerably reduce symptoms in a majority of patients with lateral humeral epicondylalgia, regardless of duration, and is possibly superior to conventional stretching.