OBJECTIVES: To evaluate the factors that limit post-cochlear implantation (CI) speech perception in prelingually deaf children. METHODS: Patients with CI were divided into two groups according to Category of Auditory Performance (CAP) scores 3 years post-CI: the poor performance group (poor performance group, CAP scores/=5, n=85). The distribution and contribution of the potential limiting factors related to post-CI speech perception was compared. RESULTS: Perinatal problems, inner ear anomalies, narrow bony cochlear nerve canal (BCNC), and intraoperative problems was significantly higher in the poor performance group than the good performance group (P=0.010, P=0.003, P=0.001, and P=0.045, respectively). The mean number of limiting factors was significantly higher in the poor performance group (1.98+/-1.04) than the good performance group (1.25+/-1.11, P=0.001). The odds ratios for perinatal problems and narrow bony cochlear nerve canal in the poor performance group in comparison with the good performance group were 4.878 (95% confidence interval, 0.067 to 0.625: P=0.005) and 4.785 (95% confidence interval, 0.045 to 0.972: P=0.046). CONCLUSION: This study highlights the comprehensive prediction of speech perception after CI and provides otologic surgeons with useful information for individualized preoperative counseling of CI candidates.