Background Endoscopic thoracic sympathicotomy (ETS) is a well-established treatment for primary hyperhidrosis and facial blushing. Not everyone has the desired local effect either from primary failure of the operation or because symptoms recurred. The incidence varies in the literature and treatment by resympathicotomy (re-ETS) is controversial. There is no information in the literature if re-ETS has any influence on compensatory sweating. Methods We conducted a follow-up study of consecutive patients who underwent re-ETS during a ten-year period (1997 to 2007). All patients received a questionnaire of primary effects and side effects. Results A total of 669 patients underwent rib-oriented ETS for primary hyperhidrosis or facial blushing. Forty-eight patients (7%) underwent re-ETS for unilateral primary failure (n = 29), bilateral primary failure (n = 6) or recurrent symptoms (n = 13) after a median of 24 months (range, 1 to 69 months). One patient died from carcinoma of the breast during follow-up. Of the remaining 47 patients, 42 (86%) answered the questionnaire. In 25 patients with unilateral primary failure (96%) symptoms improved after re-ETS. Success was lower after re-ETS for bilateral primary failure (50%) or recurrent symptoms (75%). Overall, compensatory sweating occurred in 80% of the patients after the first operation and 38% described worsening of the intensity after re-ETS, particularly after re-ETS for primary failure. Conclusions Primary technical failure is fairly common after sympathicotomy with simple transection of the sympathetic chain. It occurs at all locations of primary hyperhidrosis as well as facial blushing and re-ETS is an effective treatment. It is important to inform patients that unilateral technical failures occur and in that case compensatory sweating may worsen after re-ETS.