We report on nine patients between the ages of 21 and 39 years who were admitted to an inpatient substance abuse treatment unit for cocaine treatment. The patients' sleep was studied in the laboratory for 4 nights during the first week, and 2 nights duing the second and thrid weeks of their hospitalization. Daily mood ratings, cocaine craving scores and sleep logs were also recorded on each patient. During the first week of withdrawal, these patients had a marketdly shortened REM latency, an increased REM sleep percentage, a very high REM density and a long total sleep period time. During the third week, REM latencies were very short and total percentage of REM-sleep was increased. By week three of withdrawal the sleep continuity pattern was similar to that found in chronic insomnia, with a long sleep latency, an abnormally increased total time awake after sleep onset and a poor sleep efficiency. The subjects' ratings of cocaine craving total POMS scores and depression fell precipitously after the first week of withdrawal and were at sub-clinical levels by week three of withdrawal.