Background: Sexual attitudes are related to the expression of sexuality and have been associated with indicators for sexual health. The main aim of this study was to determine the explanatory capacity of general (i.e., erotophilia) and specific (i.e., toward sexual fantasies and masturbation) sexual attitudes on different sexual functioning dimensions (sexual desire, sexual arousal, lubrication/erection, ability to have an orgasm and orgasm satisfaction). Methods: The sample consisted of 2000 heterosexual adults (1044 women, 956 men) aged 18–83 years. Results: The explanatory models for women mainly showed that positive attitudes toward sexual fantasies (β range = −0.35, −0.249) and age (β range = −0.111, 0.086) explained sexual function. The models proposed for men revealed a more diverse pattern, although the variable essential for explaining sexual function was a positive attitude toward sexual fantasies (β range = −0.266, −0.097). Conclusions: These results indicate that specific sexual attitudes, particularly in relation to sexual fantasies, are more sensitive variables than erotophilia in examining sexual health.