BACKGROUND: Sympathectomy is an effective treatment for hyperhidrosis. The ultrasonic scalpel and electrocautery have been used for the procedure, but the use of the ultrasonic scalpel has been promoted as superior to that of electrocautery. This study explored whether a reusable electrocautery probe was equally as effective and safe as the ultrasonic scalpel for sympathectomy. METHODS: We retrospectively analyzed 140 consecutive patients. The ultrasonic scalpel (HDH 05, Ethicon Endo-Surgery, Cincinnati, OH) was used in 70 patients (group 1) and a reusable 5-mm cautery hook (Edlo, Canoas, Brazil) was used in 70 patients (group 2). End points were improvement in symptoms (% improvement score), length of stay, return to work, and complications. Data were analyzed using two-tailed t test and the chi(2) (p = 0.05 was significant). Data are mean +/- standard deviation. RESULTS: Follow-up was 27.2 +/- 8.4 months. Groups were similar in demographics, disease site, and level of sympathectomy. There was no significant difference in improvement score by site. The feet had the least improvement score (36.5% +/- 32.3%), and the hands the highest improvement score (97.0% +/- 11.3%). Length of stay was similar, 11.4 +/- 5.9 (group 1) vs 10.1 +/- 5.4 hours (group 2). Return to work in group 1 was 4.8 +/- 2.7 vs 5.7 +/- 3.6 days (p = 0.09). Group 1 had 14 complications and group 2 had 7 (p = 0.16). CONCLUSIONS: We could not demonstrate a clear advantage in the use of the ultrasonic scalpel.