Efforts are being made in the field of medicine to promote the possibility of indefinite life extension (ILE). Past research on attitudes toward ILE technologies showed that women and more religious individuals usually have more negative attitudes toward ILE. The purpose of this research was to investigate whether gender differences in attitude toward indefinite life extension technologies could be explained by religiosity, afterlife beliefs, and general attitudes toward science. In four studies (N = 5,000), undergraduate participants completed self-report questionnaires measuring their support for life extension as well as religiosity, afterlife beliefs, and attitude toward science (in Study 3). In all studies, men supported ILE more than women, whereas women reported greater belief in an afterlife. The relationship between gender and attitude toward ILE was only partially mediated by religiosity (Studies 2–4) and by attitudes toward science (Study 3).