The sample included male adolescents who had been referred for treatment between 1987 and 1993. Data were obtained from extensive and detailed retrospective review of clinical files. Subjects were divided into four subgroups: (1) incest group, subjects who sexually abused their siblings; (2) child group, subjects who sexually abused unrelated or extended family younger children; (3) peer/adult group, subjects who sexually abused peer-aged or older victims; and (4) mixed group, subjects who sexually abused victims across at least two of the other groups. The four subgroups were compared in terms of background characteristics and sexually abusive behavior. Results indicated that, when subgroups were delineated on the basis of victim characteristics, they could be reliably differentiated on several abuser and abuse characteristics. Findings were generally consistent with those described in the North American literature. Implications of the findings are discussed in relation to etiology and the development of a taxonomic classification system for British sexually abusive adolescents. 49 references and 1 table