The environmentally responsible behavior of employees at the workplace can benefit business organizations in particular and society in general. According to previous studies, positive psychological capital has been used frequently for predicting employees’ work attitudes and behaviors. In this article, we are seeking to understand whether people with a higher (lower) level of positive psychological capital − hopeful thinking, optimism, and resilience − engage more (less) in environmentally responsible behaviors in the workplace especially when they perceived a high (low) level of environmental justice To test the study hypotheses, we collected survey data from 196 randomly selected employees working in 35 private small-sized businesses in Bangladesh. This study showed that employees with higher levels of positive psychological capital engage more in environmentally responsible behaviors at the workplace. The results showed that when employees are treated fairly in the workplace, those with a high level of hopeful thinking and resilience are more likely to engage in environmentally responsible behaviors at work.