On the basis of detailed accounts of offences committed by 12 dangerous sexual offenders and of descriptions of their life histories, their responses to various tests, self-reports of offenders' sexual interests and activities, and results of phallometric evaluations, 15 expert forensic psychiatrists diagnosed whether each offender met the criteria for sexual sadism. The psychiatrists also indicated their confidence in the diagnoses they made and rated the relevance to the diagnosis of sexual sadism for various features of the offence and the offender. Results revealed unsatisfactory levels of diagnostic agreement among the psychiatrists. On the other hand, they agreed quite well on the importance for the diagnosis of several of the offence features described. Suggestions are offered for clinical practice.