Convincing fake antimalarials are a major public health disaster in SE Asia and elsewhere, with fake artesunate already being produced in industrial quantities. This has led to deaths from malaria and to inaccurate reports of artemisinin resistance. We currently have insufficient information on the scale of this problem in most malaria-affected areas, but it is expected to spread globally and to affect also fixed combination ACTs. In Africa antimalarial drugs are frequently of poor quality or expired, although fake antimalarials (in which there are usually no active ingredients) are currently less common. Unless easily affordable (i.e. heavily subsidised) ACTs are provided through both public and private outlets, essentially flooding the market, it seems likely that fake ACTs will penetrate markets rapidly as the demand for ACTs increases. Additionally ACTs have a shorter shelf-life than most alternative antimalarials, necessitating monitoring of ACT expiry dates and quality in the field. The only realistic way to prevent widespread penetration of fake and substandard drugs into the market is to detect them early, as once they become widely established, eradicating them will be virtually impossible in many countries. There are currently no good mechanisms for early detection of fake or substandard drugs in Africa.