However, only about a quarter of the patients who had traditional treatments such as drugs felt any better.
The research also suggested that fake acupuncture was nearly as effective as the real thing, and the scientists think that the body may react positively to any thin needle prick, or that it is possibly a placebo effect.
Dr Heinz Endres of the acupuncture research team said: "Acupuncture represents a highly promising and effective treatment option for chronic back pain."
Six months later 47% of the patients in the group who had real acupuncture reported a significant improvement, compared to 44% in the fake treatment group, and just 27% of those who had traditional therapy for back trouble.
Dr James Young, of Chicago's Rush University is reported to have said: "We don't understand the mechanisms of these so-called alternative treatments, but that doesn't mean they don't work."
