The number of children receiving cochlear implants (CIs) with significant disabilities in addition to their deafness has increased substantially. Unfortunately, children with additional disabilities receiving CIs have largely been excluded from studies on cochlear implant outcomes. Thus limited data exists on outcomes in this population to guide pre-implant counseling for anticipated benefits. The study objectives were: (1) evaluate differences in post-cochlear implant language skills between children with cochlear implants and developmental disabilities and age/cognitively matched controls; (2) quantify possible discrepancies between language level and cognitive level. Fifteen children with a developmental disability who received a CI were matched 1:1 on nonverbal cognitive ability and age to hearing controls. Language was evaluated using Preschool Language Scale-IV and reported as language quotients. Multivariable mixed models for matched pairs analyzed differences in language levels between groups. No significant differences were seen between CI and control groups regarding insurance, maternal education, or family income level. Results of the multivariable models indicated that compared to matched controls, the CI group had significantly lower mean receptive (24.6 points, p = 0.002) and mean expressive (21.9 points, p = 0.001) language quotients after controlling for confounders such as number of therapies and weekly hours in therapy. Significant discrepancies between language level and cognitive level were seen among CI participants only. Compared to age- and cognitively matched controls, children with CIs had significantly lower language levels with delays disproportionate to their cognitive potential. Mechanisms behind this performance-functional gap need to be understood to deliver appropriate intervention strategies for this special population. (Contains 4 figures and 3 tables.)