Despite growing numbers of drug users in prisons all over the western world, drug exchange behind bars has received little scholarly attention. The few studies that exist describe the prison drug economy as mainly following market-based principles of exchange. However, ethnographic fieldwork in a closed Norwegian prison reveals something different: prisoners share their drugs, rather than selling them. In this article, I describe and try to explain this ‘culture of sharing’. Drawing on anthropological theories of exchange, drug sharing is understood as continuous gift-giving. The gift perspective allows us to see how sharing is shaped by motives of caring, compassion and solidarity, while it simultaneously emphasizes the self-interest embedded in such drug exchanges. The article argues that sharing is a highly effective form of drug exchange because there is a strong commitment to reciprocate when a prisoner receives drugs. The ‘culture of sharing’ is both contingent upon and produces social relations between prisoners. On the one hand, it offers an inclusive and solidary community for drug using prisoners; on the other hand it is upheld by strong social controls, by which deviations from accepted norms of conduct (i.e. failing to share) are sanctioned in a variety of ways.

The article demonstrates that an unbalanced and control-dominated approach to prison-based OMT may have the opposite effect of what is intended.

Aims: The research on motivations and meanings associated with drug use in prisons has received little scholarly attention. Particularly, there are few studies analysing drug use in prisons from the perspective of both prisoners and prison officers, and in the context of prisonbased drug rehabilitation. This article explores prisoners and prison staffs perceptions on why drug use occurs in prison. Methods: The data is derived from participant observation and qualitative interviews (N ¼ 35) conducted during eight months of ethnographic fieldwork in two drug rehabilitation programmes in a closed Norwegian prison. Findings: Prison staff emphasises drug addiction and prisoners troubled life trajectories when explaining in-prison drug use. Prisoners, on the other hand, explain that drug use can be (a) a way to alleviate some of the pains of imprisonment; (b) an integral part of social life in prison; (c) a route to status in the prisoner community and (d) a defiant way to subvert institutional rules and expectations. Conclusions: Prison staff tends to privilege pre-prison characteristics when explaining prisoners' drug use, whereas prisoners tend to privilege how the prison context motivates and give meaning to their drug use. Implications for penal policy and practice are discussed.