This study examined the influence of phonological working memory on sentence comprehension in children with specific language impairment (SLI). Fourteen children with SLI and 13 with normal language (NL) participated in two tasks. In the first, a nonsense word repetition task (index of phonological working memory), subjects repeated nonsense words varying in length from one syllable to four. In a sentence comprehension task, subjects listened to sentences under two conditions varying in linguistic redundancy (redundant, nonredundant). On the nonsense word repetition task, between- and within-group analyses revealed that subjects with SLI repeated significantly fewer 3-syllable and 4-syllable nonsense words. On the sentence comprehension task, between- and within-group analyses determined that subjects with SLI comprehended significantly fewer redundant (longer) sentences than nonredundant (shorter) sentences. A positive correlation was found between subjects' performance on the nonsense word repetition and sentence comprehension tasks. Results were interpreted to suggest that children with SLI have diminished phonological working memory capacity and that this capacity deficit compromises their sentence comprehension efforts.