Previous research and clinical impression indicate two possible predictors of gynephilic preference among offenders against female children: (1) the occurrence of the offense within a father‐daughter (or stepdaughter) relationship, and (2) victimization of only one child. Validation of these putative predictors was by phallometric test results of a total of 187 male adult subjects: 95“incest”offenders against female children, 54 such non‐incest offenders, and 38 offenders against adult females. Each of these predictors showed to be valid in its own right, and the interaction of the two did not increase prediction potential.