The proposal of the current study is to analyze the relations between lexical and syntactic knowledge and the ability of deaf children to draw inferences from text reading. We selected a sample of 15 individuals with bilateral and pre-speech deafness, with losses of 70 dB or more in their better ear and with digital hearing aids and/or cochlear implant. All of them are in different levels of primary school. Each participant was evaluated with several standarized tests: PROLEC-R, PPVT-III and CEG.The findings showed differences in ability to draw inferences from texts. The grammatical comprehension competence is a better predictor of reading comprehension abilities than receptive vocabulary competence, in order to make inferences from written language, especially in expository texts.