The nocturnal sleep patterns of 10 elective herniorrhaphy patients were documented by continuous, 8 hour polygraphic recordings from night 1 of hospitalization until discharge on day 4 or 5. Subjects showed a dramatic loss of REM sleep and stages III and IV and major increases in time awake and drowsy for the first 2 postoperative nights, with a gradual return toward normal sleep over the hospitalization period. The significance for healing of the loss of stages REM, III, and IV is discussed, especially with regard to hospital procedures and the use of medications.