UNLABELLED: Individuals with cancer are disproportionately affected by sleep disturbances, relative to the general population. These problems can be a consequence of the psychological, behavioral and physical effects of a cancer diagnosis and treatment. Sleep disturbances often persist for years and, when combined with already high levels of cancer-related distress, may place cancer survivors at a higher risk of future psychopathology, health problems and poorer quality of life. It is important to develop and evaluate treatments that comprehensively address the common symptom profiles experienced by cancer survivors. METHODS: This study is a randomized controlled non-inferiority trial comparing Cognitive Behavior Therapy for Insomnia (CBT-I; a known efficacious treatment) to Mindfulness-Based Stress Reduction (MBSR; a treatment with demonstrated potential). This design can efficiently compare these two treatments directly and determine whether MBSR performs to the same standard as CBT-I for the treatment of insomnia with additional benefits of reducing cancer-related distress. Participants are randomly assigned to an 8-week CBT-I or MBSR group. Sleep indices are measured using subjective (sleep diaries) and objective (actigraphy) assessment tools. The primary outcome is insomnia severity. Secondary outcomes include sleep quality, symptoms of stress, mood disturbance, mindfulness, and dysfunctional beliefs and attitudes toward sleep. Assessments are completed at three time periods: pre-treatment, post-treatment and at 3month follow up. CONCLUSIONS: Considering the high prevalence of distress and sleep disturbances in the cancer population, should MBSR produce sleep effects comparable to CBT-I, it may be more comprehensive - making it the treatment of choice for addressing cancer-related psychological sequelae.