Despite the recent interest in user-generated online reviews, understanding how various dimensions of ‘the message’ (online review) may affect consumers’ perceptions of a review’s trustworthiness, and whether the latter shapes attitudes and subsequent behaviors. To fill this gap, a 2x2x2 scenario-based online experiment was designed exposing participants to real user-generated TripAdvisor.com reviews, and an online questionnaire was used to evaluate antecedents and consequents of review trustworthiness. Using PLS-based structural equation modeling (SEM), our findings offer a comprehensive framework of the review characteristics—timeliness, accuracy, and reviewer credibility—that drive overall perceptions of review trustworthiness and jointly predict nearly 50% of the variance in this construct. Furthermore, our findings show that the mediating role of review usefulness on the relationship between trustworthiness and brand attitude is further moderated by the sentiment of the reviews—positive and negative. Brand attitude ultimately predicts over 80% of the variance in booking intention.