According to the domain-specific, multilevel homework model proposed in the present study, students' homework effort is influenced by expectancy and value beliefs, homework characteristics, parental homework behavior, and conscientiousness. The authors used structural equation modeling and hierarchical linear modeling analyses to test the model in 2 studies with 414 and 1,501 8th graders, respectively. In line with the authors' assumptions, most intercorrelations observed between corresponding homework variables across 2 school subjects were small to moderate, conscientiousness and homework motivation proved to be strong predictors of homework effort, and perceived homework quality varied considerably between classes and predicted homework motivation and behavior. Findings highlight the need to take into account the domain specificity and multilevel character of homework variables when analyzing students' homework behavior.