Straight leg raising test(SLR) is a useful clinical test to demonstrate an inflammatory compressive process across a spinal nerve roots. In a retrospective study of 44 patients(men 18, women 26) suffering from low back pain this symptom was evaluated. Radiologic findings were classified by the hernia size and electrodiagnostic studies were classified by the grade of abnormal spontaneous activities. Two aspects were investigated: 1) the correlation between straight leg raising test and radiologic findings, and 2) the correlation between straight leg raising test and electrodiagnostic study. The limitation of the SLR test was not correlated to size or position of the hernia, however, electrodiagnostic findings was well correlated. It must be presumed that additional factors, such as inflammatory reactions affecting the nerve roots, are of importance for the magnitude of SLR test.