In this chapter we w i l l review some of the different strategies that can be used to reduce the spread o f H I V infection amongst injecting drug users. A l l o f these are based upon the concept o f 'harmminimization'. Harm-minimizat ion has two complementary dimensions: the first, which falls into the category o f primary prevention, involves persuading individuals not to start injecting ill icit drugs. The second aims to reduce the harm associated w i th injecting drug use, both for the individual and the community.