Over two decades, the importance of coaches as potential agents in the prevention of drug use amongst athletes has been emphasised. This article examines the published evidence on coaches' knowledge, attitudes and beliefs towards doping in sport. A systematic search strategy was followed. Research questions and relevance criteria were developed a priori. Potentially relevant studies were located through electronic and hand searches limited to English language articles published between 1990 and Jan 2011. Articles were assessed for relevance by two independent assessors and the results of selected studies were abstracted and synthesised. Outcomes of interest were knowledge, attitudes and beliefs in relation to doping in sport. Four studies met the inclusion criteria and were examined in detail. Samples reflected a range of coaches (n = 566) drawn from Norway, Italy, France and Hong Kong. The investigations varied with respect to outcome focus and quality of evidence. Despite the influential role that coaches might play in an athlete's life, few studies have examined their doping-related knowledge, attitudes and beliefs. While the existing empirical research posits support for the anti-doping movement, it also exposes a limited knowledge of doping effects or governance. The current evidence-base makes it difficult to plan targeted education to span coaching contexts. Addressing this situation in a more systematic and thorough fashion appears warranted.