This study aimed to investigate the characteristics of those who engage in online sexual activities and who are sexually compulsive according to the Kalichman sexual compulsivity scale. It also aimed to investigate if online sexual activities had changed the sexually compulsive respondents' offline sexual behaviors, such as reading adult magazines, viewing adult movies, and/or having casual sex partners. Data were collected in 2002 through an online questionnaire in Swedish, which was administered via the Swedish portal Passagen.se. Approximately 6% of the 1458 respondents who answered the 10-item sexual compulsivity scale were defined as sexually compulsive. A multivariate regression analysis showed sexually compulsives more likely to be men, to live in a relationship, to be bisexual, and to have had an STI. The time spent online for sexual purposes was found to be a measure of the kind of sexual activity rather than a measure of online sexual compulsivity. A bivariate analysis of nominal data showed that engagement in online sexual activities made respondents quit, decrease, maintain or increase their offline sexual behaviors. Sexual compulsive respondents were found to increase their offline pornography consumption to a greater extent than did non-sexually compulsives.