Resumen: The Interpersonal Exchange Model of Sexual Satisfaction Questionnaire (IEMSSQ) is one of the few instruments that has been developed from a theoretical model and assess sexual satisfaction. In addition, it has been successfully validated in Spanish heterosexual population. The objective of this study is to adapt and examine its psychometric properties (reliability, evidence of validity, and measurement invariance across sexual orientation and sex) in gay people in a relationship. Method: A sample of 1,820 adults, of whom 50% are gay people and 55% men, answered the Spanish version of the IEMSSQ. In addition, subjects with gay orientation answered the Massachusetts General Hospital-Sexual Functioning Questionnaire and the Dyadic Adjustment Scale. Results: When comparing by sex and sexual orientation, the IEMSSQ has a strict invariant structure. Its reliability is good, and the evidence of construct and concurrent validity is adequate. However, the components of equality are moderate. Conclusions: The IEMSSQ makes it possible to compare the sexual satisfaction between gay/heterosexual men and women, presenting good psychometric properties in gay people, constituting an useful instrument in the clinical and research field. Idioma: Inglés DOI: 10.1016/j.ijchp.2019.07.005 Año: 2020 Publicado en: International Journal of Clinical and Health Psychology 20, 2 (2020), 140-150 ISSN: 1697-2600 Factor impacto JCR: 5.35 (2020) Categ. JCR: PSYCHOLOGY, CLINICAL rank: 14 / 131 = 0.107 (2020) - Q1 - T1 Factor impacto SCIMAGO: 1.578 - Clinical Psychology (Q1)