OBJECTIVE: Insomnia is common in patients with cancer. It has a multifactorial etiology that may include the disease process, adverse effects of anticancer therapies, and/or an association with other comorbidities. The purpose of this review was to identify risk factors for insomnia and suggest optimal management strategies. METHODS: We conducted a systematic literature review to elucidate the risk factors for insomnia and sleep disturbances in patients with solid tumors. The effects of sleep medications in this population were also described. RESULTS: A total of 75 publications were evaluated, including those on breast, lung, gynecologic, brain, head and neck, gastrointestinal, prostate, thyroid, and mixed cancers. We classified the factors related to insomnia or sleep disturbance in cancer into four categories: (1) patient demographic characteristics (e.g., age, marital or socioeconomic status); (2) mental state (e.g., depression or anxiety); (3) physical state (e.g., fatigue, pain, or restless legs syndrome); and (4) anticancer treatment-related (e.g., use of chemotherapy, opioids, or hormone therapy). Overall, literature on the pharmacologic treatment of insomnia is extremely limited, although some efficacy data for zolpidem and melatonin have been reported. CONCLUSIONS: Demographic characteristics, physical and mental distress, and anticancer treatments are all risks for insomnia in patients with cancer. The limited evidence base for pharmacologic therapy in this patient population means that healthcare professionals need to implement a comprehensive and multidisciplinary pathway from screening to management.