Abstract Study Objectives: To compare the efficacy of telephone-delivered cognitive-behavioral therapy for insomnia to an information pamphlet control on sleep and daytime functioning at pretreatment, posttreatment, and 12-wk follow-up. Design: Randomized controlled parallel trial. Setting: N/A. Participants: Thirty individuals with chronic insomnia (27 women, age 39.1 ± 14.4 years, insomnia duration 8.7 ± 10.7 years). Interventions: Cognitive behavioral therapy for insomnia (CBTI) delivered in up to eight weekly telephone sessions (CBTI-Phone, n = 15) versus an information pamphlet control (IPC, n = 15). Measurements and Results: Sleep/wake diary, sleep-related questionnaires (Insomnia Severity Index, Pittsburgh Sleep Quality Index, 16-item Dysfunctional Beliefs and Attitudes about Sleep), and daytime symptom assessments (fatigue, depression, anxiety, and quality of life) were completed at pretreatment, posttreatment, and 12-wk follow-up. Linear mixed models indicated that sleep/wake diary sleep efficiency and total sleep time improved significantly at posttreatment in both groups and remained stable at 12-wk follow-up. More CBTI-Phone than IPC patients showed posttreatment improvements in unhelpful sleep-related cognitions (P < 0.001) and were classified as “in remission” from insomnia at follow-up (P < 0.05). Posttreatment effect sizes on most daytime symptoms were large (Cohen d = 0.8–2.5) for CBTI-Phone patients and small to moderate (Cohen d = -0.1–0.6) for IPC patients. All CBTI-Phone patients completed posttreatment and 12-wk follow-up assessments, but three IPC patients discontinued the study. Conclusions: The findings provide preliminary support for telephone-delivered CBTI in the treatment of chronic insomnia. Future larger-scale studies with more diverse samples are warranted. Some individuals with insomnia may also benefit from pamphlet-delivered CBTI with brief telephone support.