OBJECTIVE: Verbal communicative competence is the main objective after early cochlear implantation in deaf children. However, there are currently no validated instruments to assess a child's real-world communicative abilities. We adopted a rigorous methodological approach to systematically develop the Functioning after Pediatric Cochlear Implantation instrument (FAPCI), a family-centered communicative performance scale based on a conceptual model of functioning established by the World Health Organization. DESIGN: Qualitative instrument development was based on a systematic review of the literature, focus groups, and semistructured interviews with the parents of 2- to 5-yr-old children with cochlear implants and deafness experts. Further refinement and testing of the psychometric validity of the draft instrument was conducted using factor analysis and a cross-sectional sample of 75 parents of children with cochlear implants. Nonparametric and parametric regressions were then performed to investigate the association of FAPCI scores with duration of cochlear implant use to provide preliminary evidence for the instrument's nomological validity. RESULTS: The final 23-item, parent-proxy FAPCI instrument represents a unidimensional scale of the real-world communicative performance of 2- to 5-yr-old children with cochlear implants. The scale demonstrated excellent reliability (Cronbach's alpha >or=0.86), and there was strong evidence supporting the instrument's nomological validity. FAPCI scores were positively associated with duration of implant use (p < .001), and 4 yr of implant use were required before maximal FAPCI scores were achieved. CONCLUSIONS: Verbal communication is a critical developmental domain that allows for optimal future emotional, cognitive, and behavioral growth. The FAPCI instrument is the first validated instrument ever designed to assess real-world communicative performance of a child with a cochlear implant. The systematic approach taken to development may enable FAPCI to be sensitive to other communication-related disorders commonly seen in childhood or to serve as a model for the development of other disorder-specific instruments.