This research goals to find out (1) The influence of work environment and work discipline on professionalism (2) The effect of the work environment and work discipline and professionalism on performance. (3) The work environment and work discipline on account of nurses' professionalism in Mamuju Regional General Hospital. This research was conducted from August to September 2019 at the Mamuju Regional General Hospital by taking 221 people and a total sample of 143 people. This research used the Slovin formula. The research method used is a descriptive-analytical census method using path analysis and calculation operations using the SPSS 16 program. Based on the study results, it is known that the work environment and work discipline have a significant effect on professionalism. Work environment, work discipline, and professionalism have a substantial impact on nurse performance. The work environment and work discipline have an indirect influence on the account through the professionalism of nurses. Professionalism is proven as an intervening variable or variable that reinforces the work environment's impact and work discipline on nurse performance.