The factor structure of a parent-report measure of child homework problems, the Homework Problems Checklist (HPC), was examined in a geographically and ethnically diverse sample of children with attention-deficit/hyperactivity disorder (ADHD). This measure was completed by the parents of 579 children ages 7.0–9.9 diagnosed with ADHD Combined Type as part of the multimodal treatment study of children with ADHD (MTA). Results replicated previous work showing two salient factors that measure homework completion behaviors (Factor I) and homework management behaviors (Factor II). This two-factor solution remained consistent when examined across child sex and ethnicity subgroups. Analysis of patterns revealed that homework problems are greater for children in higher grades and that children with ADHD and comorbid learning disabilities experience significantly more homework problems than children with ADHD alone. This study also replicated previous work showing that homework problems and ADHD inattentive symptoms are highly correlated whereas correlations between homework problems and hyperactivity and impulsivity are low to moderate. Implications of the findings for the assessment of homework problems in children with ADHD and for intervention are discussed.