This multi-institutional sleep study involved two phases aimed at investigating sleep alterations in patients with any stage of breast and lung cancer. The first phase of this study used an 82-item, 20-minute telephone survey to elicit information regarding the impact of sleep disturbances on a convenience sample of 150 patients. Of these patients, 44% reported a sleep problem during the month before the interview. Significant relations included these: report of sleep problems prediagnosis over the past month (x = 5.82; p = 0.02), duration of sleep medication use and frequency of sleep problem (r = 0.58; p = 0.05), age and severity of sleep problems (r = 0.38; p = 0.05), and frequency and severity of the sleep problem over the past month (r = 0.21; p < 0.10). Communication with health care providers occurred in 16.6% of patients reporting a sleep disturbance. The second phase of this study explored the type, frequency, and severity of sleep problems and perceptions of causation, support, and methods of coping with the sleep problem. A qualitative approach to the problem was used in this phase. A one-time telephone interview of 42 patients, derived from a convenience sample, revealed a 45% prevalence of sleep problems a month before the interview. A qualitative analysis of the responses suggested that sleep problems are related to experiences of other symptoms and perceptions of cancer and treatment. Content analysis of the responses identified the following categories: figuring out the reason, seeking help, seeking support and relation to the overall cancer experience.