Deriving the meaning of unknown words from context and its relationship to text comprehension was investigated in 24 individuals with Down syndrome and in 24 typically developing children matched for the Peabody Picture Vocabulary Test (PPVT) score. The study consisted of three phases. Unknown words were identified during the first phase (PPVT). Those words were presented embedded in brief linguistic contexts during the second phase. Recognition (maintenance) of word meanings was verified in the third and final phase. Both groups of participants recognized the meanings of a noteworthy number of words in contexts and a high percentage of these was maintained when they were presented at a later date without the support of context. Over and above group differences and basic linguistic skills, text comprehension seems to predict the ability to use context. Context provides the semantic information necessary to extract word meaning by activating relevant world knowledge. (Contains 4 tables.)