Parathyroid autotransplantation (PTHAT) during thyroidectomy has been shown to reduce the incidence of permanent hypoparathyroidism. Although selective PTHAT is most commonly adopted, the value of routine PTHAT has not been well documented. Methods. From January, 1998 to March, 1999, an operative strategy incorporating routine autotransplantation of at least 1 parathyroid gland was used during thyroidectomy. The postoperative outcome of patients (n = 118) was evaluated and compared with patients (n = 271) operated during a policy of selective PTHAT (January, 1995 to October, 1997). Results. Two or more parathyroid glands were autotransplanted in 26 patients (22%) while 92 patients (78%) received autotransplantation of 1 parathyroid gland. Postoperative hypocalcemia occurred in 29 patients (25%) and 2 patients (1.7%) had permanent hypocalcemia develop. When a policy of selective PTHAT was adopted, 98 patients (36%) underwent PTHAT, and 5 patients developed permanent hypocalcemia (1.8%). The incidence of postoperative hypocalcemia was higher in patients who underwent routine PTHAT (25%) compared with that in patients who underwent selective PTHAT (15%) (P = .014). In addition, the operating time was significantly longer when routine PTHAT was adopted (153 minutes vs 130 minutes; P < .001). Conclusions. A low incidence of permanent hypoparathyroidism can be achieved by either routine or selective PTHAT during thyroidectomy but routine PTHAT is associated with a high incidence of postoperative hypocalcemia. (Surgery 2001;129:318-23.)