Background: Mutations in the TMPRSS3 gene, although rare, can cause high frequency hearing loss with residual hearing at low frequencies. Several previous studies have reported cochlear implant (CI) outcomes for adults with TMPRSS3 mutation with mixed results. Although some studies have suggested that TMPRSS3 is expressed in spiral ganglion cells, it remains unclear if previously reported poor CI outcomes in this population were secondary to long durations of deafness or to the effects of the TMPRSS3 mutation. To date, no studies in the literature have reported CI outcomes for children with TMPRSS3 mutation treated with CI. Objective: The current case series aimed to describe outcomes for three children with sloping hearing loss caused by TMPRSS3 mutation who underwent bilateral CI. Study Design: Case series. Setting: Academic medical center. Patients: Three children (3–4 yr) with TMPRSS3 mutation and normal sloping to profound high frequency hearing loss. Interventions: CI and electric acoustic stimulation (EAS). Main Outcome Measures: Outcome measures were residual hearing thresholds, speech recognition scores, and electrode placement determined via intraoperative CT imaging. Results: All three children maintained residual acoustic hearing and received benefit from EAS. Mean change in low-frequency pure-tone average was 17 dB. Mean postoperative word and sentence recognition scores in the bilateral EAS condition were 80 and 75%, respectively. Conclusions: Results indicate that CI with EAS is an appropriate treatment for children with TMPRSS3 genetic mutation. Pediatric results from this case series show more favorable CI outcomes than are currently reported for adults with TMPRSS3 mutation suggesting that the intervention may be time sensitive. Address correspondence and reprint requests to Jourdan T. Holder, Au.D., Department of Hearing and Speech Sciences, 1215 21st Avenue South, Medical Center East, South Tower, #9302, Nashville, TN 37232-8605; E-mail: jourdan.t.holder@vumc.org Financial Material & Support: NIH R01 DC13117; PI: R.H.G., PhD. Institutional Review Board: IRB# 130229. Conflict(S) of Interest to Declare: None directly related to this case series. J.T.H.: consultant for Advanced Bionics and Cochlear; A.R.: consultant for Advanced Bionics, Cochlear, MED-EL, Stryker, Grace Medical, Cook Medical; R.H.G.: advisory board for Cochlear, Advanced Bioincs, and Frequency Therapeutics; R.F.L.: consultant for Advanced Bionics and Cochlear. Copyright © 2020 by Otology & Neurotology, Inc. Image copyright © 2010 Wolters Kluwer Health/Anatomical Chart Company