The purpose of this research was to provide a comprehensive description of complement-clause production in children with language impairment. Complement clauses were examined with respect to types of complement structure produced, verb use, and both semantic and syntactic accuracy.A group of 17 children with language impairment (mean age = 6;10 [years; months]) was compared with a group of 17 younger children with typical language development (mean age = 4;6). Examples of both nonfinite complements with different subjects and sentential complements involving a range of complement-taking verbs were collected using specially designed elicitation tasks.The children with language impairment were able to construct both types of complement clauses, had access to a range of verbs that are utilized within these constructions, and had knowledge of the grammatical constraints imposed by these verbs. However, they were more restricted in their production of sentential complements and produced significantly fewer semantically accurate complements (both finite and nonfinite) than the children with typical language development.Children with language impairment evidenced deviant rather than merely delayed development in the area of complement-clause production. Complex sentences such as complement clauses need to be targeted in language intervention programs.