Few studies have examined the relationship between customer injustice and employees' retaliatory counterproductive behaviors toward customers, and those that have done so have been conducted in a Western setting. We extend these studies by examining the relationship in a Singaporean context where retaliatory behaviors by employees might be culturally constrained. While the previously established positive relationship between customer injustice and counterproductive behaviors was not replicated using peer‐reported data from employees across two hotels in Singapore, we found that individuals' self‐efficacy and perceived social support moderated it. Specifically, the injustice‐to‐counterproductive behaviors relationship was positive for individuals with high self‐efficacy, and for those who perceived high levels of supervisor social support. The findings offer insights into when Singaporean employees and, potentially, employees from other Confucian Asian societies will retaliate against customer injustice, and provide practical implications of how managers can help employees cope with customer injustice.