This paper examines whether increasing the frequency of testing deters athletes from doping. Since data is not available to analyze this problem directly, an indirect approach is required. We use the relationship between testing and Olympic performance to infer the relationship between testing and doping. This requires a variety of assumptions, the most important of which is that doping improves Olympic performance. The results suggest that in some sports, such as track & field (athletics) and wrestling, carrying out more tests does deter athletes from taking drugs. In other sports in which doping is believed to be more common, though, there is no evidence of a negative relationship between testing and doping. This is notably the case in cycling. This suggests that for some sports, increasing the frequency of testing may be a simple solution to the problem of doping. In other sports, though, the problem may have deeper roots.