In Germany, the substitution of methadone for heroin abusers has arisen recently and has resulted in various medicolegal problems. Normally, these concern methadone-associated deaths, or the prescription of methadone resulting in criminal prosecutions concerning physicians. Not to be forgotten is the problem of driving while taking methadone. In the years 1997-2001, we detected methadone in the blood of 398 cases that were analysed by the Institute of Legal Medicine, Bonn. Methadone was the only drug in only 18 cases. In most of the cases, up to five additional drugs were also being taken: benzodiazepines (61%), ethanol (40%), morphine (39%), cannabinoids (35%), cocaine (28%), anti-depressants (3%), and amphetamines (2%).