Introduction: 10 years ago, Meston and Buss (Arch Sex Behav 2007;36:477-507) identified 237 reasons for having sex. Since then, only a few studies have built on the analyses of differences in sexual motivation. Aim: To replicate the YSEX? in a broader sample of women and men of different ages. Methods: Women and men younger than 18 (n = 141), 18 to 22 (n = 1,039), 22 to 55 (n = 2,804), and at least 55 (n = 667) years old completed an online survey about their reasons for engaging in sex during the past year. Main Outcome Measures: The YSEX? inventory was assessed to measure sexual motivation. The taxonomy consists of 4 main factors (physical, goal attainment, emotional, insecurity) and 13 subfactors. Results: 4,655 participants took part in...