Psychological-psychiatric factors have a different effect on sexual functioning in men and women. This research aimed to examine the association between psychopathological dimensions and dimensions of sexual functioning in Spanish young adults in two studies. Study 1 examined sexual functioning and psychopathological dimensions in 700 women and 516 men. Study 2 conducted an experimental laboratory task to evaluate subjective sexual arousal and genital sensations when watching visual sexual stimuli in a subsample of participants from Study 1 (143 women and 123 men). As a result, the first study showed that depression and anxiety-related symptoms had a negative effect, both in men and women, and having a partner had a positive influence on the dimensions of sexual functioning. The second study showed that anxiety symptoms were positively associated with subjective sexual arousal in both men and women, and anxiety was associated with the assessment of genital sensations in men. The differences between the results of anxiety may be explained because sexual arousal was evaluated in general terms in Study 1, whereas it was evaluated as a state in Study 2. These findings confirm that the presence of psychopathological symptoms contributes to sexual functioning, as well as the necessity of strengthening mental illness prevention programs that include sexual health components.