Due to the inseparable nature of human services, customers participate in the service delivery process, engaging in interpersonal contact with service employees and physical contact with the service settings provided by service firms. During this contact process, customers desire to have influence or control over the service encounter situation or environment, and their responses to the service experience vary depending on the degree of perceived control over the service encounter. Based on Bagozzi's (1992) self-regulation process of attitude theory, this study examines how the physical environment and crowding perceived by customers at service encounters affect their perceived control over service encounters, and how perceived control influences the positive/negative emotions they experience during the service encounter, as well as their behavioral intentions (repurchase intention, favorable word-of-mouth intention) and behavior (voluntary behavior). For the empirical analysis, the proposed model was evaluated and hypotheses were tested using two service customer groups (patients at an oriental medicine hospital and administrative service applicants at a government office). The analysis results confirmed that customers' perceived control plays an important role at the service encounter in both groups. The perceived control variable showed statistically significant relationships with antecedent physical environment factors as well as emotions, behavioral intentions, and behavior variables, and the significance patterns were very similar across both groups. According to structural equation modeling (SEM), perceived control was strongly and positively influenced by the positive physical environment, but was not significantly influenced by crowding. Unlike prior studies that only addressed pleasure, this study found that perceived control had a differentiated effect: a positive (+) influence on positive emotions and a negative (−) influence on negative emotions. Furthermore, perceived control had a positive (+) influence on both behavioral intentions and behavior. Although not previously discussed, a strong association was confirmed between positive emotions and customers' voluntary behavior. This is an important finding confirmed through this study, and greater attention to these relationships appears necessary.