This study aims to predict Generation Y customers’ acceptance of user-generated content (UGC) websites by integrating an extended technology acceptance model (TAM), trustworthiness of online reviews, and cultural consensus and cultural consonance theory. To collect data, a free listing method was first used to recognize our ad hoc domain, i.e., the factors that determine the trustworthiness of online hotel reviews among Generation Y in South Korea, from an emic perspective. Based on the free listing results from 39 individuals, an online survey was conducted with 273 samples using a self-administered questionnaire. Cultural consensus analysis was conducted to determine whether there is a shared cultural model in trustworthiness factors among participants, and cultural consonance values were calculated. Then, a structural equation modeling technique was used to estimate how the proposed model explains the collected data. Results indicate that an agreed-upon cultural model of trustworthiness of online hotel reviews exists among sample members. Cultural consonance of trustworthiness was found to constitute a significant antecedent of perceived ease of use and attitude towards websites in the extended TAM model. This study can contribute to predict Generation Y customers’ acceptance of UGC websites and offer meaningful implications for sustainable tourism management, particularly when cultural variables are considered.