The Double Standard Scale (DSS) is an instrument used to assess the sexual double standard, and appropriate, to make comparisons between sexes. The interest in the study of the sexual double standard is a variable associated with sexual health. Although, several studies have been interested in the psychometric properties of the DSS, none of them has been raised considering their equivalence between men and women, or between adolescents and adults. This study has the objective, examine the factorial invariance and analyze differential item functioning by sex and age. A sample of 2,248 Peruvian subjects (1.063 adolescent - 46% boys and 54% girls- and 1.185 adult -51% men and 49% women-) was evaluated. Results obtained demonstrate a perfect fit factorial equivalence by categorizing of items about gender, and the differential item functioning is negligible. In contrast, with respect to age, invariance is discarded, but the differential item functioning is negligible. In conclusion, DSS scores can be contrasted between genders, but not between adolescents and adults.