Recently, great interest in value co-creation has been revealed among both academics and practitioners in the hotel sector. However, few studies are analyzing the consequences of co-creation behavior from the customer perspective in “green” (environmentally-friendly) hotels. This study explores the relationships between value co-creation and guest trust, satisfaction, and loyalty in the context of green hotels. Moreover, the role of trip purpose and generational cohort as moderating variables in these relationships is tested. The data are collected through a personal survey from 309 Spanish hotel guests, and the partial least square structural equation model (PLS-SEM) is employed to test the research hypotheses. The results of this study reveal that guest participation in the hotel’s process of value co-creation positively affects guests’ trust, satisfaction, and loyalty. Additionally, both trust and satisfaction are positively linked with customer loyalty. The findings here also suggest that only customers’ age moderates some of the relationships considered (i.e., trust–loyalty and satisfaction–loyalty). To practice, this study provides managerial implications to help hoteliers use value co-creation to develop competitive strategies that will generate more value for tourists due to the positive effects of these strategies on tourist trust, satisfaction, and loyalty.