The International Olympic Committee (IOC) published the first list of doping classes in 1967. Since that time, there have been significant problems associated with doping control in sport. Sport is a high profile, internationally recognised activity. However, operational inconsistencies exist between countries and between sports federations. Endogenous substances, such as testosterone, human growth hormone (hGH) and erythropoietin (Epo) present particular problems in determining what constitutes 'normal' levels in athletes. In addition, there is no reliable method available for the detection of hGH and Epo through urine testing. Athletes continue to test positive for banned drugs that are available over-the-counter despite their having been taken inadvertently, without intent to enhance performance. Marijuana use is becoming widespread in society and the impact of this in sport is becoming evident. Doping control, through the IOC list, must continue as a primary objective for the IOC and the sports federations. Constant vigilance and a continued willingness to respond rapidly to change is a prerequisite for such a list. The IOC appears to recognise this need. There are, however, more fundamental issues to be considered. The concept of doping control must be supported by high quality research, effective education and international collaboration. More research is needed into the factors which induce an athlete to take drugs and into the effect, if any, that education on drugs is having on competitors. The most important area for change is the overriding need for international collaboration between the IOC, governments and sports federations. This applies to uniformity in the rules and regulations, consistency in the application and level of sanctions and cooperation on the dissemination of information and development of education policies.