ABSTRACT The Protective + Risk Observations For Eliminating Sexual Offense Recidivism (PROFESOR) is designed to identify risk and protective factors for individuals aged 12–25 who have engaged in, or have been accused of engaging in, illegal or otherwise abusive sexual behaviour. Unlike most risk assessment tools which are designed to predict the future, the PROFESOR is designed to identify dynamic protective and risk factors that can inform interventions that will facilitate sexual and relationship health and, thus, eliminate sexual offense recidivism. The rationale for the development of the PROFESOR is outlined, and an investigation of the tool’s reliability is presented. For this study, 58 individuals (aged 12–20 years; M = 16.3; SD = 1.63) in residential treatment for male youth who have engaged in sexually harming behaviour were rated by a pair of clinicians from a group of 15 clinicians (therapists and their supervisors). Unlike typical investigations of interrater agreement where a small number of raters utilise identical file material, PROFESOR ratings were made based on the clinicians’ working knowledge of the individuals in their care. Excellent interrater agreement was demonstrated with the Total score, as were significant item-total correlations and internal consistency estimates, indicating encouraging evidence of the reliability of the PROFESOR. PRACTICE IMPACT STATEMENT This paper identifies the limitations of risk prediction tools for adolescent sexual recidivism and outlines the rationale for the development of the PROFESOR, an assessment tool designed to inform intervention goals and intensity by identifying both risk and protective factors. Data from therapists and supervisors at a residential treatment facility indicated encouraging evidence of the reliability (i.e. interrater agreement, item-total correlation, and internal consistency) of the PROFESOR.