The Integrated Theory of Sexual Offending (ITSO) claims that sexual offending is the consequence of three sets of continuously interacting factors: biological factors, ecological factors, and neuropsychological factors. According to the ITSO, clinical symptoms, such as deviant arousal or offense related thoughts, can emerge from the interaction between genetic factors, social learning, and neuropsychological factors. Following a review of the many factors impacting biological and ecological functioning, the authors discuss how all these factors interact to impact the core neuropsychological functions underpinning human action. Current frameworks that attempt to explain sexual offending are reviewed, as are neuroscientific accounts of human behavior and the effects of genetic determinants on sexual behavior. After the ITSO model is introduced, its relationship to other theories of sexual offending is considered in terms of its potential for unifying a range of competing theories into one explanative model. It is hoped that greater research will refine the ITSO and that the ITSO will facilitate the development of tailored treatment programs. Figure, references