Abstract The paper analyses nineteenth century opium trade statistics, and Registrar-General's annual reports of death from opium poisoning. It contributes historical material to the contemporary debate on the effects of legislative control of drug use. It assesses the reality of nineteenth century concern about the free availability of opium and patent medicines containing it. The study concludes that, despite the unease of doctors and public health reformers, the system of open sale which operated until the passing of the 1868 Pharmacy Act, in some respects worked well. Legislation introduced to deal with the problem of open sale as perceived by contemporary society undoubtedly had an impact. Some problems were thereby ameliorated; if not resolved; new ones emerged. Infant deaths were curbed, but accidental deaths were hardly affected, and more adult males poisoned themselves. A move to unrestricted forms of the drug, through patent medicines like chlorodyne, was also clear. A permanent decline in overall mortality from opium began only at the turn of the century. Legislative control did have its effects, even if it also exacerbated or altered the problems with which it was meant to deal. Its greatest impact came when it was in tune with changing economic and social circumstances which were making opium and self-medication less important. An obligation for stricter control, however, arose from Britain's adherence to the international narcotics control movement. The war-time restrictions on cocaine and opium and the 1920 Dangerous Drugs Act were passed when the general narcotic mortality rate was at its lowest ever level.