Objectives: The purpose of this study was to investigate the developmentof lateralization skills in children who received bilateral cochlearimplants (CIs) in sequential operations. Methods: The lateralizationskills of 9 children with a mean age of 4.1 years at the first surgeryand 5.5 years at the second surgery were assessed at 3 time intervals.Children were assessed with a 3-loudspeaker setup (front, left andright) at 0.9 years (interval I) and 1.6 years (interval II) after thesecond implantation, and after 5.3 years of bilateral implant use(interval III) with a 9-loudspeaker setup in the frontal horizontalplane between -90 degrees and 90 degrees azimuth. Results: Withbilateral implants, a significant decrease in lateralization error wasnoted between test interval I (45.0 degrees) and 11 (23.3 degrees), witha subsequent significant decrease at test interval III (4.7 degrees).Unilateral performance with the CI did not improve significantly betweenthe first 2 intervals; however, there was a bias of responses towardsthe unilateral side by test interval III. Conclusions: Thelateralization abilities of children with bilateral CIs develop in arelatively short period of time (1-2 years) after the second implant.Children appear to be able to acquire binaural skills after bilateralcochlear implantation.