This study examines customer response to human and robot service encounters under different service uncertainty levels. Guided by uncertainty management and service encounter needs theories, we argue that service uncertainty will moderate the effect of service encounters (humans vs. robots) on the perceived utility and rapport of customers. The results of two experiments show that under high service uncertainty, robots are perceived by customers to have higher utility than humans. Meanwhile, when the service uncertainty level is low, human agents will be perceived to demonstrate higher rapport than robots. The results further show that service uncertainty can moderate the mediating effect of perceived utility and rapport in the relationship between service encounters and customer satisfaction. Acknowledging service uncertainty, we identify the theoretical implications of human–robot interactions and provide practical suggestions to hospitality and service companies for devising effective strategies to manage the technological transformation of their service delivery.