To investigate factors that predict partnered sexual activity in men and women aged 60–75 years from Norway, Denmark, Belgium, and Portugal. A cross-sectional study including national representative samples of people aged 60–75 years from Norway (676 men, 594 women), Denmark (530 men, 515 women), Belgium (318 men, 672 women), and Portugal (236 men, 273 women). Data were collected by means of anonymous questionnaires. Generally, across countries, the two most important predictors of partnered sexual activity were positive attitudes toward “Sex for well-being,” and sexual problems in the partner. Other important predictors of partnered sexual activity included positive attitudes toward sexual changes due to aging, previous sexual activity, and relationship happiness. The sexual function of the partner and people's own sexual attitudes were highly predictive of partnered sexual activity.