With the development of information technologies and increasing interest in sustainability, many companies have adopted smart work as a sustainable human resource practice. Moreover, the outbreak of Covid-19 has further promoted smart work in the workplace. However, the benefits and disadvantages of smart work are still under debate. In this regard, this study attempted to delve into how to enhance smart work implementation by exploring employees’ subjectivity. Hana Tour, which is considered a good model of smart work in South Korea, was selected as a sample company. Q-methodology was employed to listen to employees’ subjective opinions about smart work that they experienced. This study identified five types of smart work perceptions, namely, “self-development and energy saving,” “quality of personal life,” “job satisfaction,” “work engagement,” and “work–life balance”. Based on these five types, the theoretical and practical implications are discussed in the last chapter. Interestingly, the results showed that employees were not well aware of smart work effectiveness as one of the environmental protection practices in sustainability management paradigms. Another notable result was that employees were not concerned about the potential penalties of their engagement in smart work. During the current COVID-19 pandemic, the study’s findings are beneficial to the improvement of smart work implementation as a sustainable HRM practice in business.