There is a convergence of data from various sources suggesting that there are meaningful differences among the benzodiazepines with respect to their attractiveness as drugs of abuse for drug abusers. Laboratory studies of subjective and reinforcing effects in drug abusers, interviews with drug abusers, clinical judgment of medical professionals, and epidemiological studies all indicate that diazepam, in particular, has a greater abuse liability than many of the other benzodiazepines. Some of the available data also suggest that lorazepam and alprazolam are more diazepam-like in having relatively high abuse liability, while oxazepam, halazepam, and possibly chlordiazepoxide, are relatively low in this regard. These differences in abuse liability among benzodiazepines are analogous to the widely recognized differences in abuse liability within the barbiturate class that have proved to be important in helping guide clinicians' drug prescribing practices.