Based on social exchange theory, this study investigates the antecedents and consequences of a frontline employee’s trust-in-supervisor and a frontline employee’s trust-in-coworker in a single framework. A personally administered survey was conducted to collect data from 203 frontline employees of coffee shops in the Republic of Korea. Covariance-based structural equation modeling was applied using AMOS 21.0 to explore the proposed relationships. The results show that abusive supervision is negatively related to frontline employee’s trust-in-supervisor, whereas supervisor support and communication quality have significant positive effects on frontline employee’s trust-in-supervisor. Similarly, coworker ostracism has a significant negative effect on frontline employee’s trust-in-coworker, whereas coworker harmony and communication quality have significant positive effect on frontline employee’s trust-in-coworker. Finally, the results show that a frontline employee’s trust-in-supervisor predicts a frontline employee’s supervisor cooperation, and a frontline employee’s trust-in-coworker leads to a frontline employee’s coworker cooperation.