Several sociodemographic, drug use pattern, and clinical variables were investigated in two groups of heroin addicts. Inclusion in one group or the other depended on the addict's attitude toward or against receiving treatment for the addiction. Those who rejected treatment differed significantly in the following: they were younger and belonged to larger families; they started cannabis and amphetamine use earlier, and used for a longer time; they used cocaine and heroin more frequently, and alcohol less frequently; and they suffered more often from a number of somatic and personality disorders. Implications for future research on the addiction are discussed.