The objective of this study was to assess the mediating effect of job satisfaction in the relationship between Organizational Justice and Organizational Commitment in selected public service bureaus, Bahir Dar city. A total of 205 questionnaires were distributed to employees of working in public service bureaus in Bahir Dar and from the distributed questioners 185(90.24%) were collected and used in the data analysis. Likert scales were used for data collection which contains Organizational Justice, Job Satisfaction and Organizational Commitment questionnaires. The researcher has used a cross sectional survey with descriptive and explanatory research design. Furthermore the researcher used a quantitative research approach. Results of the level of Organizational Justice, job satisfaction and Organizational Commitment are all moderate. The result in the Pearson correlation coefficient revealed that there is a positive significant correlation between Organizational Justice, job satisfaction and Organizational Commitment. The path analysis result of the present study shows that job satisfaction partially mediates the relationship between Organizational Justice and Organizational Commitment.