In a sample of 104 Norwegian ninth-grade students, we examined whether perceived reading efficacy and reading task value uniquely predicted the comprehension of a social studies text after variance associated with gender, achievement in the domain, topic knowledge, deeper strategies, and surface strategies had been removed through forced-order hierarchical multiple regression analysis. Results showed that even after removing variance from these variables, the motivation constructs accounted for additional variance. However, only reading task value was a statistically significant positive predictor of reading comprehension, whereas the relationship between reading efficacy and reading comprehension did not reach statistical significance. Thus, reading task value seems particularly important because it can override the contributions of other important constructs. In terms of education, the findings suggest that an emphasis on cognitive constructs such as prior knowledge and strategic text-processing should not make us overlook the specific importance of promoting motivation for reading comprehension. (Contains 2 tables.)