This study explores the relationship of participative budgeting on budgetary slack in the public sector in Indonesia, by examining the roles of job satisfaction on these variables. A total of 185 budget managers of regional work units in the in North Maluku province government, Indonesia, participated in the survey. The effective rate of return was 82.52 percent. A structural equation modeling was used to examine the direct and indirect effects of participative budgeting on budgetary slack. In particular, the study gives empirical evidences that participative budgeting factors affect budgetary slack mediated by intervening variables factors of job satisfaction. The results revealed the significantly negative effect of participative budgeting on budgetary slack, the significantly positive effect of participative budgeting on job satisfaction. This result affirmed the significantly negative impact of job satisfaction as a mediating variables on budgetary slack. However, the results could not find the indication of moderating effect of job satisfaction in the relationship of these variables.