This paper compares the offender and offense characteristics of 30 sexually sadistic criminals studied by Dietz et al. with those of 29 sexually sadistic criminals and 28 nonsadistic sexual offenders from the Royal Ottawa Hospital. We examined whether the characteristics noted by Dietz et al. would be found among a less violent group of sadistic offenders and also to what extent these characteristics were specific to sexual sadism. Results suggest some offender and offense characteristic are specific to sexual sadism and that others appear to be common to sexually aggressive offenders more generally. In addition, there were a number of characteristics found exclusively among the most violent offenders described by Dietz et al. An explanation of these results in terms of a biopsychosocial understanding of sexual sadistic offenders is provided.