Background: Periodic limb movement disorder (PLMD) has recently emerged as a relatively frequent and markedly underdiagnosed condition in children that induces arousals and sleep fragmentation and leads to poor learning and behavioral problems. Because a cost-effective and widely available alternative to pediatric polysomnography is needed for diagnosis of limb movement disorders, this study sought to examine whether periodic leg movements in children could be reliably identified using recently developed actigraphy software.Methods: Bilateral actigraphs were worn around the feet by 99 children ages 4-12 years during standard clinical overnight polysomnography, which included bilateral anterior tibial electromyogram (EMG).