The purpose of this study was to extend the research on adolescents' motivation for reading by examining important group differences and the relation of motivation to standardized achievement. Adolescents (N = 406) ranging from grade 7 to grade 12 completed a self-report survey that assessed 13 different aspects of their reading motivation including multiple forms of expectancy beliefs, value, achievement goals, and social goals. Group comparisons indicated important differences between readers who had struggled and those who were more adequate readers, but relatively few differences based on gender or grade in school. Regression analysis showed that the motivational beliefs as a group, and perceived control individually, were able to predict students' performance on a standardized measure of reading comprehension.