Abstract: This study explains the findings of the research on implementation of Integrated River Basin Management (IRBM) in Langat river basin, Malaysia. This study utilized institutional analysis and development framework to identify institutional challenges associated with IRBM implementation in the study area. Three categories of action arena were defined and scope for stakeholder participation in decision making was identified. This analysis revealed that polycentric institutional arrangements under Federal administration are capable to coordinate and integrate river basin management by extending the scope for iterative learning processes that could address institutional challenges for adaptive and ecosystem based management approaches. Using stakeholder interview data, binary logit regression model and ordinal regression model analyses were carried out to find out present effect of influencing factors of IRBM implementation and outcome of present learning environment in study area. R2 value for these model analyses were 0.41 and 0.27, respectively at 1% significance level. It was found that social learning could significantly influence IRBM implementation in the study area (Odd ratio for social learning was 17.11). It has opened up scope for future research in the study area. Finding of this study is envisaged to be useful to those who are concerned to strategize IRBM and sustainable development and further research on LRB and else where.