the literature already points out that the family is often the main obstacle that prevents elderly people from experiencing their sexuality. However, there are no studies that identify the effects of sexuality on family functioning. analyzing the effects of sexuality on family functionality and on the quality of life of the elderly. a cross-sectional study conducted with 692 elderly people between the months of July and October 2020 by self- administered instruments. Data were analyzed using the Kruskal-Wallis test, Pearson correlation and structural equation modeling. the elderly with some degree of family dysfunction had a worse experience in sexuality and a worse quality of life. The affective relationships domain of sexuality was the only one to exert a positive effect, from moderate to strong magnitude on family functionality (PC=0.472 [CI95%=0.301-0.642] p<0.001). Quality of life, in turn, had a positive effect, from weak to moderate magnitude, in all domains of sexuality: sexual act (PC=0.339 [CI95%=0.190- 0.488] p<0.001); affective relationships (PC=0.117 [CI95%= -0.041-0.275] p<0.001) and physical and social adversities (PC=0.150 [CI95%=0.074-0.226] p<0.001). sexuality among the elderly can be explored more frequently in health services, as it exerted positive effects on family functionality and quality of life in this population. It is expected that with the results of this study, there is an appreciation of the theme in care services and that sexuality in old age is explored with the elderly, especially in primary health care.