This study examined the influences of reading decoding skills and world knowledge on third graders' comprehension of narrative and expository texts. Children read a narrative text and an expository text. Comprehension of each text was assessed with a free recall prompt, three cued recall prompts, and 12 multiple-choice questions. Tests from the Woodcock-Johnson III Tests of Achievement (Woodcock, McGrew, & Mather, 2001) were used to assess reading decoding skills and world knowledge. Comprehension was better for the narrative text than the expository text, and the effects of reader competencies depended on text genre. Comprehension of the narrative text was most influenced by reading decoding skills. In contrast, expository text comprehension was most influenced by world knowledge. (Multiple-choice questions are appended. Contains 1 endnote and 5 tables.)