Background: Carpal Tunnel Syndrome (CTS) is the most prevalent peripheral mononeuropathy. Khadar is the word used for CTS in Iranian Traditional Medicine (ITM), and the effect of cold Temperament (Mizaj) as one of its causing factors is emphasized. Objectives: The purpose of this study was to determine the Mizaj of patients suffering from CTS. Methods: This study was conducted at Imam Khomeini hospital, Tehran, Iran. General Mizaj of 170 patients with CTS was assessed using the Salmannejad questionnaire. Electrophysiological testing and clinical examination were done and patients were categorized into mild, moderate and severe CTS. Findings were analysed with SPSS software. Results: Regardless of CTS severity, total preponderance of cold-wet Mizaj was observed (n=49, 28.8%). Considering CTS severity, cold Mizaj and wet Mizaj were the highest prevalent singular Mizaj in all groups of CTS severity. Cases with coldwet Mizaj made up the highest compound Mizaj percentage in all categories of CTS severity (mild=32.35%, moderate=27.3%, severe=29.2%). However, according to statistics, the difference of warmness-coldness, and wetness-dryness scores among different groups of CTS severity was not significant (P˃0.05). Conclusion: Cold-wet Mizaj was most prevalent in our study. Mizaj identification may help individuals at high risk for CTS to prevent the disease by Mizaj correction. Especial recommendations according to Mizaj may help patients, too.