Background:Patient’s final satisfaction with endoscopic carpal tunnel release (ECTR) is still unpredictable. The study aims to find the predictive factors for satisfaction in patients with carpal tunnel syndrome (CTS) treated by ECTR using the Boston CTS questionnaire.Methods:We conducted a retrospective chart review of 37 patients (55 hands) who received ECTR and completed Boston carpal tunnel questionnaire at preoperative visit, 1 month and 6 months after operation while a telephone interview was conducted at 2 years after operation. Independent risk variables, including mean symptom severity scale, functional status scale, each item in questionnaire at all the time points, ASA physical status scale, age, gender, dominant site lesion, bilateral lesions, duration of symptoms and anesthesia method were recorded. Final outcome was determined by the patient’s satisfaction at the interval of 2 years. Predictors to outcome were analyzed by stepwise multiple regression analysis and tested with Pearson correlation test. A p value of less than 0.05 was considered significant.Results:The severity of hand or wrist numbness during the daytime (Q6, explained 6.5% variances), the severity of numbness or tingling at night (Q9, explained 16.2% variances), the functional status of writing (q1, explained 13.9% variances), carrying grocery bags (q7, explained 13.6% variances) had significant predictive value (p<0.001). Other factors were not significant in the analysis including ASA, gender, age, dominant site lesion, bilateral lesions, anesthesia method and duration of symptoms.Conclusions:Boston questionnaire is a simple and reliable tool with high predictive values to evaluate patient’s outcome and satisfaction in ECTR.