This article qualitatively examines the content of online forum discussions of ketamine use in light of theories of Beck's risk society. Based on 59 discussions from a reputable harm reduction website, the study finds that online ketamine users are very knowledgeable about the harmful effects of the drug. They view risk and harm as stemming from: (1) the direct physical effects of ketamine; (2) the environment of use; and (3) the economic, social and legal consequence resulting from use. Moreover, they believe that the harmful consequences of use can be mitigated through controlled and safe use practices. These methods of mitigation include practices that ensure the purity of the drug, use in controlled environments with trusted individuals, and limiting the amount and frequency of use. Ultimately, the study finds that online discussions provide a rich exemplar of Beck's theory of contested definitions of risk and harm.