Skill in generating inferences predicts reading comprehension for students in the elementary and intermediate grades even after taking into account word reading, vocabulary knowledge, and cognitive ability (Cain et al., "Journal of Educational Psychology, 96," 671-81, 2004; Kendeou et al., "Journal of Research in Reading," 31, 259-72, 2008; Oakhill and Cain, "Scientific Studies of Reading," 16(2), 91-121, 2012; Oakhill et al., Language and Cognitive Processes, 18, 443-468, 2003). While research shows that struggling readers are less likely than proficient readers to make inferences when reading text (Cain et al., Memory and Cognition, 29, 850-859, 2001; "Oakhill, British Journal of Educational Psychology," 54, 31-39, 1984), struggling readers may also benefit more from inference instruction than do proficient readers (Hansen and Pearson, "Journal of Educational Psychology," 75(6), 821-829, 1983; McGee and Johnson, Educational Psychology, 23(1), 49-59, 2003; Raphael and Pearson, "American Educational Research Journal," 22(2), 217-235, 1985; Yuill and Oakhill, "Applied Cognitive Psychology," 2, 33-45, 1988). This synthesis assessed (a) the effectiveness of inference instruction in improving reading outcomes for struggling readers and (b) the features of instructional interventions (e.g., duration, type of instruction) that were associated with improved outcomes. One single-case design and eight experimental group design studies were synthesized. Mean effect sizes for group design studies ranged from g?=?0.72* to g?=?1.85* for researcher-developed measures of inferential reading comprehension and from g?=?-0.03 to g?=?1.96* for standardized measures of reading comprehension. The percentage of non-overlapping data for the study that employed a single-case design was 100% for all measures.