Polygraphic records of night sleep taken in 10 alcoholics for three days after the cessation of the alcohol intake showed the following disorders: a disturbance of the sleep cyclic organization, a sleep fragmentation, a considerable prolongation of the drowsiness (stage I), a sharp reduction of the delta-sleep stages. One to two weeks after the abstinence onset stage I was still too long, and the delta-sleep stage remained shorter than normal, despite a clinical improvement and cessation of complaints.