The successful implementation of sustainability initiatives throughout a company can positively influence business performance, especially in complex conditions of transition economies, such as Belarus. Nevertheless, prior studies provide limited evidence regarding the relationships between employees’ perceptions about company’s sustainability performance and the relevant determinants of their behavior. The main purpose of this study is to investigate the impact of company’s sustainability performance on employees’ job satisfaction, work meaningfulness and consequently their internal brand commitment in a transition economy. The findings demonstrate significant causal effects between the four dimensions of sustainability performance, and positive effects of job satisfaction and work meaningfulness on internal brand commitment.