BACKGROUND Nonspecific low back pain is a very common disorder for which no completely satisfactory treatment has been established. A randomized, double-blind, controlled clinical trial was design to assess the efficacy of neuro-reflexotherapic intervention in the treatment of this condition. METHODS Ninety-one patients with a confirmed diagnosis of nonspecific low back pain were referred for treatment from primary health care facilities in the Spanish National Health System. A total of 43 patients were assigned to the control group and 48 to the treatment group. Patients in the treatment group received a single neuro-reflexotherapic intervention. Patients in the control group underwent a similar procedure, although inappropriate zones were stimulated. Patients in both groups were allowed to continue drug and physiotherapy treatments prescribed by their general practitioners. According to the design the study was ended when statistically significant and clinically evaluable results were obtained in an analysis carried out half way through the study. RESULTS Participants underwent clinical evaluations on three occasions: immediately prior to intervention, immediately after and on day 30 afterwards. Patients in the treatment group showed immediate clinically and statistically significant improvements (p < 0.0001) in pain, muscular contracture and mobility, allowing them to discontinue pharmacological treatment and keeping them free of symptoms during the study period. CONCLUSIONS According to results of this study, neuro-reflexotherapic intervention has proved to be an effective method for treating low back pain.