Objective: Criteria for paediatric cochlear implant candidacy continue to evolve, as research indicates an increasingly broad range of children for whom the procedure can produce benefit. Children with difficulties in addition to their deafness, or global developmental delay, are not routinely excluded. The aim of this study is to explore the association between developmental delay in young paediatric cochlear implant candidates and progress with the device. Materials and methods: The study is a retrospective case series analysis of 32 children, aged between 1.2 and 2.8 years at pre-implant assessment. Children were assessed using the Schedule of Growing Skills II and IT-MAIS before implantation. Progress in speech perception and Speech Intelligibility was monitored using the E2L toy test and Speech Intelligibility Rating (SIR), respectively, 1 and 2 years after switch-on. Results: Data were subjected to regression analyses, with either the E2L or SIR as the outcome variables, and variables derived from the Schedule of Growing Skills II (general development and cognitive functioning), IT-MAIS, age at switch-on and average aided hearing loss pre-implant as the predictor variables. In each analysis the strongest (and statistically significant) predictors of speech perception and Speech Intelligibility were the measures of general development and cognitive functioning, accounting for around 40% of the variance in outcomes. Conclusion: This study indicates the value of routinely assessing the general development of young paediatric cochlear implant candidates, as part of the pre-implant decision-making process. Significant developmental delay is predictive of poor outcomes, but children with a mild delay do make appreciable progress. Developmental assessment of young deaf children is therefore important in terms of candidacy decisions and counselling parents regarding potential benefit from a cochlear implant. (C) 2006 Elsevier Ireland Ltd. All rights reserved.