Resumen: Objectives: The authors conducted an initial validation of the Arizona Sexual Experience Scale (ASEX) and examined the sexual function of Spanish and Portuguese young adults. Methods: Participants were 523 Spanish and 595 Portuguese heterosexual young adults who completed a background questionnaire, the ASEX, and measures of sexual sensation seeking, excitation, and inhibition. Results: The ASEX showed good reliability and validity. Participants reported good sexual function. The most prevalent difficulties in men were related to desire and orgasm, and to orgasm and satisfaction in women. Conclusions: This is a psychometrically sound instrument to assess sexual functioning in Spanish and Portuguese young adults. Idioma: Inglés DOI: 10.1080/19317611.2016.1259706 Año: 2017 Publicado en: INTERNATIONAL JOURNAL OF SEXUAL HEALTH 29, 2 (2017), 155-167 ISSN: 1931-7611 Factor impacto JCR: 1.014 (2017) Categ. JCR: SOCIAL SCIENCES, INTERDISCIPLINARY rank: 53 / 98 = 0.541 (2017) - Q3 - T2 Categ. JCR: PSYCHOLOGY, CLINICAL rank: 102 / 127 = 0.803 (2017) - Q4 - T3 Categ. JCR: PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH rank: 123 / 156 = 0.788 (2017) - Q4 - T3 Factor impacto SCIMAGO: 0.451 - Gender Studies (Q2) - Social Psychology (Q2) - Reproductive Medicine (Q3) - Dermatology (Q3) - Public Health, Environmental and Occupational Health (Q3)