This study aimed to investigate the effects of authentic leadership and organizational culture, perceived by nurses working at medical institutions, on work meaning and work engagement, which are job attitudes, through the mediators, leader-member exchange and psychological capital, in 301 nurses working at three general hospitals with over 300 beds. The analysis results showed that authentic leadership perceived by nurses had a direct effect on enhancing leader-member exchange (β=0.95, p=0.004), and organizational culture had a direct effect on increasing psychological capital (β=0.56, p=0.004). Organizational culture had an indirect effect on increasing work meaning (β=0.32, p=0.004), and psychological capital had a direct effect on increasing work meaning (β=0.56, p=0.004). Work meaning had a direct effect on enhancing work engagement (β=0.89, p=0.004), and organizational culture had an indirect effect on enhancing work engagement (β=0.41, p=0.004). In addition, psychological capital had a direct effect (β=0.62, p=0.004) and an indirect effect (β=0.33, p=0.004) on enhancing work engagement. Therefore, it is necessary to develop human resource management programs that consider authentic leadership of the leader and organizational culture, and mediating effects of leader-member exchange and psychological capital in order to improve job attitudes of nurses.