Better Nights/Better Days, a distance intervention for insomnia in school-aged children (with and without attention-deficit/hyperactivity disorder [ADHD]), was evaluated to determine its effectiveness on children's sleep and psychosocial functioning. A single center, parallel group design randomized controlled trial (stratified on ADHD diagnosis) was conducted. Parents were randomized to intervention (n = 31) or waitlist control (n = 30), and completed questionnaires administered over the phone at baseline, postintervention (2 months), and follow-up (6 months). Actigraphy was also collected. The intervention consisted of a five-session manual and weekly telephone coach support. The intervention group demonstrated a significant reduction in sleep problems and improved psychosocial functioning at postintervention and follow-up. Actigraphy results indicated improved sleep onset, but not sleep duration. Children with and without ADHD responded in a similar manner to this intervention. Parents provided high satisfaction ratings. This intervention holds promise as an accessible, sustainable, and effective program to address insomnia in school-aged children.