The objective of our study is to evaluate the detection capacity of Colour Duplex Scanning (CDS) in helping to diagnose Pudendal Neuralgia (PNa) by Pudendal Nerve Entrapment (PNE). This technique is being compared to complete Neurological Criteria (NC) based on Diagnostic Score (DS) and Electroneuromyography (ENMG) and secondly, to the results of surgery. This is a prospective study, on a consecutive series of 96 unselected patients evaluated by both CDS and NC. The CDS examinations were performed by the same operator who was unaware of the NC. The DS and the ENMG were read by a practitioner who was unaware of the CDS findings. The Peak Systolic Velocity (PSV) and the Systolic Ascension Time (AT) were the vascular criteria. Inadequate examinations were neither repeated nor removed from the analysis. Of 166 Internal Pudendal Arteries (IPAs) explored by CDS, 163 were visualised on their whole course, leading to a 98% feasibility. Of the 67 PNE identified by NC, 60 cases of Pudendal Vascular Entrapment (PVE) were detected by CDS, leading to a 89.6% sensitivity and a 67.4% specificity. Currently, there is no gold standard that can diagnose PNa by PNE with certainty. CDS is a non-invasive technique, demonstrating high diagnostic value to confirm PNE. In this study, we determined a new objective diagnostic criterion, the Pudendal Artery Ratio (PAR), which is very strong at diagnosing PNE but needs to be validated by further studies.