Opiate dependence is a chronic illness that may be approached by different treatment programs, such as drug-free or harm reduction programmes (i.e. substitution). Nevertheless, the treatment programs available are not working for some heroin dependent persons. In this context the programs of heroine prescription are developed as an alternative to drug users with severe medical, psychological and social problems. This treatment, as a program or a trial, is now offered in a few European countries (United Kingdom, Switzerland, Netherlands, and Spain). Heroin trials could increase the scientific knowledge, provide more clinical evidence and reach conclusions about the therapeutic utility of this programs, and the opportunity to offer a new hope and the chance to improve the quality of life of heroin users.