Objectives: Patients with hyperhidrosis suffer from an extreme perspiration that cannot be aligned with natural or situational standards. Endoscopic sympathectomy is a meaningful option for palmar and axillary hyperhidrosis. A standardized method of monitoring the immediate intraoperative success has not been established yet. The presented investigation shows one proposed sollution by monitoring skin surface temperature. The main aspect is to demonstrate a significant rise in temperature with utility for monitoring the immediate success of surgery. Methods: Twenty patients with primary hyperhidrosis were observed and treated in a standardized setting against a control group (n = 10). We obtained diverse data that permit determination of a point of time of measurement of surface temperature and definition of a degree of temperature variance. Results: After 5 minutes a significant change of 0.5? Celcius was noted on the palms; after 10 minutes on average 1.2? Celcius. Axillary temperature had significantly changed after 10 minutes with a mean temperature variation of 0.8? Celcius on the right side and 0.6? Celcius on the left side. Conclusions: Under consideration of appropriate time intervals of measurement and determined changes in surface temperature an early control of correct clip application in ETS is possible. In the palmar aspect an increase of 0.5? Celcius at an 5 minutes interval, and more than 1? Celcius at 10 minutes after placement of the clip as compared to basic values before application of the clip can be proposed.