The diagnostic assessment of low back pain should predominantly be based on history and clinical examination rather than on imaging studies. The problem of diagnostic imaging in low back pain is related to the high rate of asymptomatic morphological alterations in the lumbar spine. The diagnosis should therefore not be guided by findings in imaging. The imaging studies (standard radiographs and MRI) should verify the clinically suspected diagnosis and further lead to imaging guided injection studies (e.g. nerve root block, facet joint block, sacro-iliac joint block, provocative discography) to differentiate between symptomatic and asymptomatic morphological alterations. With longlasting local anaesthetics and steroids it is possible to achieve a diagnostic as well as a therapeutic effect.