Background. Despite their safety and effectiveness in thyroid surgery, the previous harmonic scalpel instruments are considered large and cumbersome by several surgeons. An innovative technical improvement of the device has been made available since 2008. The objective of this study was to compare the results of total thyroidectomy using the new harmonic scalpel (FOCUS) with that with the previously available device (HARMONIC ACE). Methods. A prospective randomized study of all total thyroidectomies between February and July 2008 was conducted. Patients (n = 90) were randomized to undergo total thyroidectomy FOCUS with (group A, n = 45) or HARMONIC ACE (group B, n = 45). Results. No significant differences were identified between the 2 groups in toms of demographics, reoperative thyroid surgery, thyroid gland weight and diameter pathologic diagnosis, preoperative and postoperative serum PTH and calcium levels, postoperative complications, duration of hospital stay, and final outcome. The mean operative time was less in group A than group B (63 +/- 7 min vs 76 +/- 8 min, P = .009). Conclusion. The new harmonic scalpel is a useful adjunct to the armamentarium of the thyroid surgeon. It is safe, effective, and hand friendly, offering great capabilities for delicate tissue grasping and dissection. Use of this device decreased operative time compared with the previously available instrument. (Surgery 2011;149:411-5.)