In most of the world and particularly in Eastern Europe, China and India, drug resistance is increasingly seen as a major threat to tuberculosis (TB) control and even to public health and health security. What about in Africa? The conditions for creation of drug resistance exist in most, if not all, African countries, as a result of underinvestment in basic TB control, poor management of anti-TB drugs and virtual absence of infection control measures. The severity of drug resistance is increasing--following outbreaks all over the world of multi-drug resistant TB (MDR) in the 1990's, extensive drug resistant (XDR) TB has now been found in 37 countries, including South Africa. (MDR is, in essence, resistance to the most powerful first-line drugs, and XDR-TB is TB resistant to the most powerful second-line drugs as well.) Worse still, the impact of XDR-TB is magnified among those with HIV infection, giving rise to a remarkably high mortality, and exposing significant weaknesses in both HIV and TB control. In particular, the lack of laboratories capable of carrying out culture and drug susceptibility testing severely limits the capacity of countries even to detect the problem in Africa. This paper analyses the threat of TB drug resistance to health and to TB control in Africa, and puts forward measures to diminish this threat.