Only a few national cohort studies on using online pornography and buying sex have been published. The overall aim of this study, which analyzed data from a representative Danish national survey, was to provide an overview of incidence and associated population characteristics. The key aims were: first, to analyze frequencies of using online pornography and buying sex stratified by gender and other background characteristics; and, second, to investigate if and how using online pornography and buying sex were associated with sexual satisfaction, sexual activity, and violence. The findings revealed that having ever paid for sex and higher use of pornography were each associated with being male, younger, and not being in a relationship. Further, among men, having ever paid for sex and higher use of pornography were associated with not being sexually satisfied and, in part of the analysis, having committed violence to another person in the last year; however, these particular relationships were not statistically significant in the appropriately controlled regression analysis. We discuss gender, age, sexual aggression, and sexual satisfaction as factors associated with higher pornography use and buying sex.