Background: Prevalence of electrophysiological abnormalities in patients with lumbosacral radiculopathy was evaluated.Methods:A cross-sectional study was performed on 97 consecutive patients with the clinical diagnosis of lumbosacral radiculopathy. Complete neurological examinations and standard electrophysiological evaluation was performed on the patients.Results:Patients under study had the mean age of 46.4 ± 13.1 years (mean ± standard deviation). There were positive MRI findings in 64% of the patients. In 43% L5 root and in 40% S1 root was involved. Abnormal electrophysiological findings were recorded in 82% of the patients. In patients with pretibial muscle weakness, there were significant abnormalities recorded in compound motor action potential (CMAP) amplitude of the common peroneal nerve. There was significantly increased frequency of electrophysiological abnormalities in the presence of chronic clinical symptoms (P = 0.001).Conclusion:The 82% positive findings in electrophysiological studies in the diagnosis of lumbosacral radiculopathy make it an efficacious tool in the evaluation of the patients suffering from lumbosacral radiculopathy.