The present study examined the associations of 2 indicators of homework quality (homework selection and homework challenge) with homework motivation, homework behavior, and mathematics achievement. Multilevel modeling was used to analyze longitudinal data from a representative national sample of 3,483 students in Grades 9 and 10; homework effects were analyzed at the student and the class level simultaneously. Students who perceived their homework assignments to be well selected reported higher homework motivation, and homework behavior at both the student and the class level predicted later achievement at the class level. Homework assignments perceived to be cognitively challenging were differentially associated with achievement at the student and the class level. Students who perceived their homework to be challenging (student level) showed relatively poor performance, but homework challenge was positively related to achievement at the class level. (Contains 1 figure, 5 tables, and 5 footnotes.)