Students are inundated with posters, fliers, commercials, and advertisements intended to persuade. Students also are challenged to think critically about persuasion on high-stakes assessments, but their textbooks rarely include argument. Students have little experience with written persuasion and may lack the knowledge and skills necessary to comprehend and evaluate it. Research with adults has shown that prior knowledge and text characteristics affect reader persuasion. However, it is risky to design instruction for middle-school students based on adult outcomes. Thus, this study extended research on adults to middle-school students. A total of 357 middle-school students between 11 and 15 years old in grades six through eight read an argument on keeping animals in zoos structured as one-sided, two-sided refutation, or two-sided nonrefutation. Text content was emotional and factual. Students rated the persuasiveness of content during reading, rated their knowledge and beliefs before and after reading, and answered comprehension and evaluation questions. Verbal reports collected from 26 students informed how students processed persuasive text. Overall, most middle-school students' lacked adult knowledge of argument and persuasion for reasoning through the argument and its content. Most students identified persuasive text as written to inform, and selected the topic as the main point and a claim as the supporting detail. Students identified the argument in two-sided refutation more accurately. Verbal responses revealed that few students used knowledge of argument structure or persuasive content to comprehend, analyze, and evaluate. Instead, most students reacted to the content as they read and later inaccurately induced the author's purpose and argument. When evaluating premises, a majority of students selected the evidence as their source, but verbal responses indicated that students reasoned from text-based evidence, prior knowledge and their beliefs, despite selecting the evidence basis. Their particular basis depended upon the premise statement being evaluated. Students lacked knowledge of argument and persuasive content and were highly persuaded by both the emotional content and argument structure. Students rated emotional content as more persuasive than factual content. Other results suggested that one-sided argument affected students' beliefs the most. Changes in perceived knowledge mirrored changes in beliefs.