Having a satisfying sex life is important to older adults. Thus, this study aimed to provide information about the sexual satisfaction of older adults in a relationship, using the Interpersonal Exchange Model of Sexual Satisfaction (IEMSS) as a theoretical framework. Participants were 187 sexually active individuals (98 men and 89 women) in a romantic relationship (age 65–75 years). They were recruited using Amazon's Mechanical-Turk, and completed the Interpersonal Exchange Model of Sexual Satisfaction Questionnaire and two open-ended questions asking what they enjoyed most and least about their sexual relationship. On average, participants were highly sexually satisfied. In keeping with the IEMSS, greater sexual satisfaction was predicted by a more favourable balance of sexual rewards to costs, greater equality of sexual costs and higher satisfaction with the non-sexual aspects of the relationship. Four themes emerged regarding what participants liked most and least about their sexual relationship: emotional aspects of the relationship, physical aspects of the relationship, dyadic aspects of the relationship and age-related aspects of being sexual. None of the four themes were specific to men or women, although some gender/sex differences were found. The results paint a positive picture of the sexual relationships of older adults and support the utility of the IEMSS as a framework to understand sexual satisfaction in older adults.