In this meta-analysis, the authors synthesize results from 44 (quasi-)experimental studies on informational and narrative text structure interventions involving students in grades 4-6 in regular school settings. Findings show that text structure instruction had positive immediate effects on students' reading comprehension but that effect sizes varied largely across outcome measures: questions (Hedges' g = 0.25), summarization (g = 0.57), recall (g = 0.37), and knowledge about text structure (g = 0.38). However, students who received text structure instruction no longer outperformed control groups at delayed posttests. Content-related features, such as a focus on paragraph-level structure, active construction of graphic organizers, and teaching rule-based summarization techniques, moderated the effectiveness of text structure instruction, but these effects also varied across outcome measures. Instructional features moderated delayed effects: Interventions with opportunities for individual student practice resulted in higher delayed effects for comprehension questions. The authors argue that text structure instruction deserves a place in the primary school curriculum so the positive effects on reading will be maintained.