Received April 2, 2013 Revised August 8, 2013 Accepted August 9, 2013 Address for correspondence Jae Young Choi, MD, PhD Department of OtorhinolaryngologyHead & Neck Surgery, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea Tel +82-2-2228-3603 Fax +82-2-393-0580 E-mail jychoi@yuhs.ac Background and ObjectivesZZPurpose of this study is to compare the cost-effectiveness between sequential (SeqBCI) and simultaneous bilateral cochlear implantations (SimBCI). Subjects and MethodZZThis is a retrospective study of 15 patients who underwent bilateral cochlear implantations at a tertiary care facility. Nine patients with SimBCI and six with SeqBCI were included. Operation time, anesthesia time, expenses for preoperative evaluation, hospitalization time, hospital expenses and postoperative expenses were investigated. ResultsZZThe 1st, 2nd and cumulative operation time for the SeqBCI group were 181, 120 and 301 minutes, respectively, on the average. The 1st, 2nd and cumulative anesthesia time were 212, 162 and 373 minutes, respectively. The 1st, 2nd and cumulative expenses for preoperative evaluation were 1074754, 280118 and 1354872 won, respectively. The 1st, 2nd and total hospitalization time were 6.2, 4.2 and 10.4 days, respectively. The 1st, 2nd and cumulative hospital expenses were 24082713, 24158366 and 48176734 won, respectively. The 1st, 2nd and cumulative postoperative expenses were 447830, 551778 and 999608 won, respectively. For the SimBCI group, the operation time, anesthesia time, expenses for evaluation, hospitalization time, hospital expenses and postoperative expenses were 246, 280 minutes, 1396793 won, 6.2 days, 46073011 and 816121 won, respectively. On the whole, anesthesia time, hospitalization time and postoperative expenses of the SimBCI group were less than those of the SeqBCI group (p=0.01, 0.02 and 0.02, respectively). The postoperative expenses of SeqBCI were the highest during the first 4 months whereas those of SimBCI were less during the same period (p=0.03). ConclusionZZCumulative anesthesia time, hospitalization time and postoperative cost of SimBCI were less than those of SeqBCI. Our results may be useful for counseling the timing of second CI. Korean J Otorhinolaryngol-Head Neck Surg 2013;56:627-31