•A meta-analysis investigated cognate facilitation in sentence contexts.•26 Studies included in low constraint analysis; 18 in high constraint analysis.•Significant cognate facilitation effects in both low- and high- constraint sentences.•Effect sizes were moderated by constraint, task, and by language of sentence stimuli•Results are discussed within the BIA+ model of lexical access and a new framework. Research on bilingual sentence processing demonstrates effects of cross-language activation during lexical access. However, there are mixed findings regarding the ability of semantically-constraining sentences to eliminate non-selective effects. In a quantitative meta-analysis the magnitude of cognate facilitation was examined as a function of sentence constraint, task and language of the sentence native language (L1) versus second (L2) as moderator variables. Twenty-six studies met criteria for measuring cognate facilitation in low-constraint sentence contexts and 18 experiments for high-constraint sentence contexts. The weighted average effect size for both contexts was significant, but significantly smaller for high-constraint contexts. This provides evidence that semantic information from a sentence constrains cross-language lexical activation. Effect sizes were moderated by task and language of the sentence. Findings are discussed in terms of models of bilingual lexical access and a new framework for understanding the mechanism of sentence context effects is proposed.