Work life conflict is defined as a form of inter-related conflict in expectation between both work and life roles. Work life conflict has the most dominant effect on employee’s performance and their productivity by sustaining well-being of workers and lessens work stress, which in return maximize efficiency. The main purpose of this study focuses on finding out the effects of work life conflict on employee performance in the case of bank of Abyssinia, BahirDar city branches. The participants of the study were employees of bank of Abyssinia in BahirDar city branches. In order to collect data, the researcher employed simple random sampling techniques to select participants of the study and total 132 questionnaires were distributed and came out 100% response rate in addition to this the researcher used quantitative research strategy to further describe the phenomenon and applies both descriptive and explanatory approach. In addition to analyze the data SPSS version 23 were used, the reliability of questionnaire items had been tested using Cronbach's alpha, the study applied descriptive statistics, Pearson's correlation analysis and regression analysis. The result indicated that among the work life conflict factors three variables work to personal life interference (r = -0.620, p < 0.001 and β= -0.455), work overload(r = -0.669, p < 0.001 and β= -0.089) and personal life to work interference(r = -0.608, p < 0.001 and β= -0.093) have statistically and negatively predict the variation in the dependent variable(job performance) whereas one variable job autonomy(r = 0.688, p < 0.001 and β= 0.157) ha spositive relationship to the dependent variable. Based on the findings of the study, it is recommended that Top management should realize the effect of work life conflict on job performance and should implement work life balance programs, practices and policies, and also it is essential that Human resource departments are responsive to the needs and constantly changing requirements of workforce and the effect of environmental issues in order to improve programs and policies of work life balance like locally attainable flexible work time arrangements.