Sclerosing injections under ultrasonographic guidance is a new method of treatment for persistent pain in Achilles tendinosis. Good results, even superior to those of surgery, have been described. We report the outcome of 25 patients with midportion tendinosis receiving sclerosing treatment. Twenty-eight consecutive patients (29 tendons) with ultrasonographical findings of midportion tendinosis examined during the period November 2004 to November 2005 were identified in the database of the Department of Radiology, Malmö University Hospital. Twenty-five patients (26 tendons) were found suitable for treatment. Follow-up consisted of self-assessment questionnaire or phone interview. In 19 patients (20 tendons), results were good or excellent. Complications were few and mild. We conclude that sclerosing injections is a promising alternative to surgery in chronic Achilles midportion tendinosis. Our results are comparable to those obtained with surgery, but the procedure is less invasive. However, a few cases of tendinosis lack detectable neovessels and may still be candidates for surgery.