Objectives: To document the factors that influence oral language performance in Spanish and English bilingual children with a cochlear implant. Design: Using a repeated measures paradigm within a child, correlation and regression were used to analyze 4 factors that influence both Spanish and English receptive and expressive vocabulary, overall language skills, and articulation accuracy. The factors were age, duration of implantation, communication mode (total versus oral), and the amount of Spanish spoken at home. Subjects: Twelve children between the ages of 49 and 106 months who had received a cochlear implant before 36 months. All subjects scored within the normal range of the nonverbal IQ Leiter test. Main Outcome Measure: Spanish and English, receptive and expressive vocabulary, semantic and syntactic language skills, and articulation skills were measured using standardized tests, the Peabody Picture Vocabulary TestYIV, the Test de Vocabulario en Imagenes Peabody, the Expressive One Word Picture Vocabulary Test and Preschool Language ScaleYIV, and the Goldman-Fristoe Test of Articulation-2. The amount of Spanish spoken at home was obtained via parental questionnaire. Results: The raw scores of English language skills increased with increasing age and duration of implantation. Spanish skills were higher for higher Spanish spoken scores, and this effect was stronger when children were using oral communication mode. Lastly, oral communication mode had a positive effect on articulation accuracy. Conclusion: Age, duration of implantation, the amount of home language use, and communication mode influenced the overall language skills for Spanish and English bilingual children.