The aim of the present study was to investigate the prevalence of not reporting sexual attraction in the past year and its associations with factors related to partner relations as well as sexuality-related characteristics in a population-based sample of Finnish twins. The present study was based on a total of 3,540 participants (1,304 men and 2,236 women) aged 33-43 years. A total of 19 men and 73 women reported complete absence of sexual interest in women or men during the past year. Older age was associated with absence of sexual interest in the past year in women, but not men. Individuals who reported absence of sexual interest in the past year were more likely than individuals who reported sexual interest to be single, but those who were in a relationship did not express more dissatisfaction with their relationships. Individuals who reported absence of sexual interest in the past year had had fewer sexual partners and reported less experience of sexual behavior in childhood. Women who reported no sexual interest in the past year, but who were nevertheless sexually active, reported higher frequencies of sexual dysfunctions than matched controls. No significant differences regarding the tendency to fake orgasm were found between the sexually active individuals who reported absence of sexual interest in the past year and the group of matched controls. The present study suggests that absence of sexual interest may be a lifelong phenomenon which does not necessarily affect relationship satisfaction, but is associated with variation in sexual behaviors.