The relationship between benzodiazepine and regular amphetamine use was examined in a sample of 301 regular amphetamine users. Benzodiazepine use was widespread, with 37% of subjects having used them in the month preceding interview, and 55% in the preceding 6 months. Injectors of amphetamines were more likely to have ever used, and to be currently using, benzodiazepines. Comparisons of benzodiazepine users with other subjects indicated that benzodiazepine users had higher levels of polydrug use and psychopathology, as well as poorer health and social functioning than non-users. The odds of benzodiazepine using injectors having injected with a borrowed used needle in the preceding month were 3.8 times of those of non-benzodiazepine-using injectors. These results are consistent with studies of other groups of illicit drug users, such as heroin users, in indicating that benzodiazepine use is associated with greater levels of risk and psycho-social dysfunction.