Streamflow has been very useful indicator for predicting flood, especially since climate change is found to increase the flood risk in the future. Therefore, this study aims to predict the streamflow of the study area under climate change scenario using the Rainfall-Runoff Inundation (RRI) model. Langat River Basin in Selangor, Malaysia is selected as a study area due to its location and urbanised area. The data that were used in this study includes observed data obtained from Department of Irrigation and Drainage (DID) Malaysia; climate data extracted from climate models (NHRCM, MRI-AGCM3.2s, HadGEM2-ES and CSIRO-Mk3-6-0); topographic data from HydroSHEDS at 3 arc-second; land use data from PLANMalaysia; and river cross section from DID. The RRI model has successfully simulated peak streamflow (Qp) of Langat River Basin during calibration and validation period with R2, NSE and NRMSE of 0.91, 0.82 and 0.35 respectively for calibration and ranging from 0.88–0.97, 0.75–0.94 and 0.27–0.81 respectively for validation. Three out of four climate models predicted that the Qp of Langat River Basin will decrease by 4.6 to 25.9% due to climate change in the future (2080s). Nevertheless, there is also a possibility for the Qp to increase up to 26.7% as predicted by MRI-AGCM3.2s. Thus, it can be inferred that climate change will dry up or humidify Langat River Basin in the future. Based on the percentage difference, the impact can be considered low and as long as the difference is within allowable percentages, the risk of drought and flooding is minimal in Langat River Basin. Further comparison with climate data from CMIP6 is recommended for better prediction of streamflow since CMIP6 is the latest ensemble of climate models with new scenario of climate change.