In France, so called "substitution treatments" for addiction are nicotine substitutes for tobacco dependence and buprenorphine, and methadone for opiate dependence. The word "substitution" participates to the uncertainty as to the objective of such treatments. From an addiction psychiatry perspective, these treatments are of interest as pharmacological treatments for maintenance of abstinence. In such a perspective they are not changing one substance of dependence for another. The goal is to reduce craving by low potential reinforcement medications. Conditions for success are a clarification of treatment goal with the patients, adequate dosing, and time. All medical doctors may prescribe buprenorphine for treatment of opiate dependence. Supervised daily dispensing in pharmacies is useful to increase compliance and collaboration, and avoid misuse and diversion. For tobacco dependence, nicotine patch must be clearly differentiated from other nicotine substitutes like gums and inhalers that have significant reinforcing effects. Because the patch is accessible without medical prescription, many patients are not sufficiently medically supervised and dropout frequently. For patients that cannot initially accept the behavioral changes associated to the goal of abstinence, it is legitimate to truly substitute them with less dangerous reinforcing substances. This possibility exists in France only for tobacco use that can be substituted to inhaled or chewed nicotine. It is possible that some reported misuse of buprenorphine and methadone are inadequate attempts to increase the reinforcing effects of these medications.