Background: There are no articles that aim to evaluate the specific role of surgical decompression on the recovery of pain and positive sensory symptoms (PSS) in patients with brachial plexus neuropathy (BPN), as well as the relationship between pain and frequency of sensory manifestations. Methods: A prospective before and after study was performed, considering the pain intensity through the visual analogue scale (VAS), and the frequency of PSS through a proposed new scale: Sensory Frequency of Symptoms Scale (SFSS). To compare the patients before and after the intervention, a paired T-test, a Wilcoxon signed-rank test, and Cohen’s D test were made, coupled with a Spearman analysis in order to establish the relationship between pain and PSS. Results: Sixteen patients were included in the study, the clinical evaluation showed changes in pain according with VAS, going from a mean preoperative state of 8.19 to 1.31 after surgery, showing significant changes (84%, p 0.00006, \mathrm{\Delta } = 2.776). Within the PSS, a significant decrease was observed in paresthesias (74%, p 0.0001, \mathrm{\Delta } = 1.645), dysesthesias (80%, p 0.002, \mathrm{\Delta } = 1.453), and allodynia (70%, p = 0.031, \mathrm{\Delta } = 0.635). Conversely, the preoperative correlation analysis between pain and dysesthesias/allodynia showed a low and non-significant relationship (R 0.4, p > 0.05). Conclusions: Surgical decompression is an effective technique for the relief of pain and sensory manifestations in adult patients with BPN of compressive origin. No relationship was observed between pain and dysesthesias/allodynia. Therefore, during clinical evaluation, they should be considered as independent manifestations, highlighting the need to validate new scales.