Thirty-six patients with lateral epicondylitis of the elbow (19 women, 17 men, median age 48 yrs) were treated either with active laser or placebo, 18 patients in each group. The active laser was a GA-AL-AS 30 mW/830 nm low power laser (LPL). The study design was double blind and randomized. The treatment session consisted of eight treatments, two per week. Patients were irradiated on tender points on the lateral epicondyle and in the forearm extensors. Output power was 3,6 J/point. A follow up was performed by telephone, 10 weeks after the last treatment. No difference between laser and placebo was found on lateral elbow pain (Mann Whitney test, 95% confidence limits). We conclude that low power laser offers no advantage over placebo in the treatment of musculoskeletal pain as lateral epicondylitis. Further studies with low power laser treatment of musculoskeletal pain seem useless.