Chronic insomnia may be exacerbated and/or perpetuated by a variety of factors, including anxiety about sleep and misperception of sleep-wake times. Limited prior evidence suggests that providing objective feedback, based on actigraphy measures, can improve insomnia symptoms. It is unknown whether this finding can generalize to increasingly available consumer sleep monitors. We conducted a randomized cross-over wait-list control pilot study of device-based feedback for insomnia. After a seven-day run-in period of diary entries, subjects were randomized to either waitlist (sleep hygiene) or to active feedback of sleep duration with a ResMed S+ monitor. The waitlist group crossed over to active feedback after one week. Daily electronic diaries were kept throughout. Feedback was associated with significant improvements in the Insomnia Severity Index, Pittsburgh Sleep Quality Index, and Functional Outcomes of Sleep Questionnaire. These symptomatic improvements occurred despite no change in subjective (diary) or objective (device) measures of sleep latency, wake after sleep onset, number of awakenings, or total sleep time. At the exit interview, 89% reported the device feedback was useful, and 63% would consider device-based feedback as a long-term treatment for insomnia. Device-based feedback is a simple, feasible intervention that may benefit some patients with insomnia. Future studies in larger cohorts will inform predictors and durability of response.