This is a preliminary report of the sleep architecture in patients receiving radiation for unresectable lung cancer. One group of nine patients said they were good sleepers and a second group of five said they were poor sleepers. All fourteen patients slept for three consecutive nights in a sleep laboratory. No differences were found in the group means for sleep latency, REM latency or percentage of time spent in Stage I vs Stage II sleep. The cancer patient's perception of whether they slept well or poorly related solely and significantly to the amount of delta sleep. This stage of postulated anabolic and restorative sleep may be more critical for the cancer patient than for others. If substantiated, this can be an important issue in prescribing hypnotics. This quality of life issue for cancer patients deserves further study.