The benzodiazepines have been extensively prescribed for decades for vague indications such as anxiety, sleeplessness and muscle tension. Despite increasing knowledge of their adverse effects, such as sedation, psychomotor and cognitive impairment, and dependence on long-term use, and the recent advent of better alternatives, their use continues largely unabated. The paper under review assesses the sparse high-quality data related to efficacy (denoted by the dropout rate for failure to respond), effectiveness (dropout rate for any reason) and dropout for adverse effects. The conclusion is that efficacy was significantly higher for the drugs as compared with placebo; by contrast, no convincing evidence was found of any short-term effectiveness: and adverse effects were 1.5-times more frequent in the drug-treated patients. Various reasons for these results are discussed. I point out the changes in diagnostic criteria over the years and the lack of accepted methods of assessing estimates of effectiveness in clinical practice. Excessive prescribing of these controversial drugs is likely to continue.