Purpose: The purpose of this study was to validate the cauda scale (TCS) in an external population. TCS was proposed as a tool to be used to predict the likelihood of cauda equina compression.Methods: We analysed the presenting condition of consecutive patients attending the emergency department undergoing a magnetic resonance scan with a clinical suspicion of cauda equina syndrome (CES). The findings were graded according to TCS for those with and without radiological compression of the cauda equina. Logistic regression was applied to the data in accordance with the original paper.Results: Patients were included over a 14 month period (n = 313), subsequent imaging revealed CES compression in 34 cases and no CES compression in 279. The TCS proposed that small values meant a more likely diagnosis of CES, the data showed the opposite of this with the highest number of patients with CES scoring a maximal 9 on TCS (mildest symptoms).Conclusions: Our data suggests that TCS has potential limitations in identifying patients with CES and needs further work prior to implementation.