Of the many unresolved issues in relation to prion diseases, effective treatments remain an elusive exigency, although some progress has been made. This review describes disease-ameliorating therapeutic strategies reported to date in animal models of prion disease, as well as providing a brief overview of selected completed human treatment trials. Included in vivo studies have been broadly dichotomized according to the time of introduction of the treatment in relation to animal inoculation and also according to their possible principal mechanism of action, although the latter is not always entirely clear, and often there is likely to be more than one mechanism. Consequent to the pathogenic primacy of cellular prion protein (PrP(c))-to-scrapie PrP(c) (PrP(sc)) conversion, most reported treatments appear to directly target this replication process, although various other strategies, such as depletion of reaction substrates and abrogation of downstream effector pathways, have been utilized. Many factors, including experimental design, militate against reliable extrapolation of study results to the routine clinical setting or limit easy translational application to human disease. Notably problematic are approaches wherein benefit has been shown but the treatment was initiated before, at or soon after inoculation of experimental animals.