Thyroi dectomy under the effect of superficial cervical plexus block (SCPB) has met resistance. Aim: to compare variables in patients submitted to hemithyroidectomy under the effect of general anesthesia (GA) and SCPB. Case report and Methods: GA was used in 21 patients, and SCPB was used in another 21 patients. Following sedation, marcaine 0.5% with vasoconstrictor was used in the SCPB group. Intraoperative sedation with diazepam and metoprolol to control arterial pressure and cardiac frequency was given as needed. GA followed the standard method in the unit. Results: We found significant results (p<0.05, Student's ttest) for surgery time (GA -111.4 min; SCPB -125.5 min), anesthesia time (GA -154.1 min; SCPB -488.6 min), time in the surgery room (GA -15 min; SCPB -1 min), treatment costs (GA -R$203.2; SCPB -R$87.4), presence of bradycardia (GA -0; SCPB -23.8%) and laryngotracheal injury (GA -51; SCPB -0 %). We also found the following non-significant results: hospitalization time (GA -17.3; SCPB -15.1 hours); bleeding volume (GA -41,9 g; SCPB -47.6 g), size of the operative specimen (GA -52.1 cm3; SCPB -93.69 cm3) and patient satisfaction level (GA -3.8; SCPB -3.9). Conclusion: Although the incidence of bradycardia was higher (23.8%), SCPB was done for the resection of tumors measuring up to 348 cm3, at a lower cost and with no laryngotracheal injuries; these were present in 51% of patients undergoing GA.