Fifty consecutive patients with neuroradiologically confirmed lumbar disk prolapse, who responded to the first five daily physiotherapy sessions with pain centralization, were prospectively treated with mechanical physiotherapy (McKenzie). At a median follow-up of 55 weeks, there were high rates of patient satisfaction, recovery from neurological deficits, and employment, and a low rate of surgical interventions. Mechanical physiotherapy is thus a useful diagnostic tool and an effective treatment strategy for many patients with lumbar disk disease.