The purpose of this research was to analyze and explain the effect of work discipline, work environment and organizational citizenship behavior on employee performancce of PT. Cosmoprof Indokarya Banjarnegara. This research is a quantitative research using a questionnaire of 107 respondents in PT. Cosmoprof Indokarya Banjarnegara. The sampling technique Accidental sampling and Slovin formula. Data analysis used validity test, reliability test, classic assumption test, multiple linear regression test, coefficient of determination test, f test and t test. The result of this research show that work discipline has a positive and significant effect on employee performance, work environment has a positive and significant effect on employee performance, and organizational citizenship behavior has a positive and significant effect on employee performance.