The authors present five case histories illustrating controlled use of opiates ("chipping"). Long-term chippers tend to develop consistent social use patterns that permit and also limit use. The authors conclude that controlled use of opiates is possible and that large numbers of people are involved in such use, although they are hard to locate and identify. Controlled users are differentiated from compulsive users more by their development and maintenance of social drug use rituals than by such variables as availability of the drug and personality and family background of the user.