Aim: To identify the use and utility of language comprehension tests for unintelligible or non-speaking children with severe cerebral palsy (CP). Method: Severe CP was defined as severe dysarthria (unintelligible speech) or anarthria (absence of speech) combined with severe limited mobility, corresponding to Gross Motor Function Classification System levels IV to V. An electronic search in the databases of PubMed, PsychInfo, Embase, and CINAHL was made of studies published between January 1965 and December 2008. Indexing terms and free-text terms for "cerebral palsy", "language", and "instrumentation" were used. Studies were included when (1) the focus was to investigate comprehension of spoken language of children (0-18y) with severe CP, and (2) language tests were described. Results: Twelve standardized tests and five experimental instruments were identified. All standardized tests were developed for children without limited mobility. Only the Peabody Picture Vocabulary Test-Revised was frequently used and feasible for older children with severe CP (greater than 9y). The other tests were used occasionally. To establish utility, adaptations of standardized test procedures were necessary. Interpretation: Language comprehension tests for children with severe CP are scarce. A language comprehension test specifically designed for these children is warranted.