Under the auspices of AFD and IRD, a collaborative research project aims to support the monitoring and modeling of marine debris in the Indonesian Seas and in the South East region. The project goals at strengthening Indonesian institutions awareness and knowledge about marine pollution by plastics, in order to implement mitigation strategies. Due to their high durability and relative low cost, the plastic production keeps increasing every year, and a substantial quantity of it eventually enters and accumulates in the oceans. Emissions and transport of such litter materials are complex and depend on waste management, population density and hydrology, but the majority of these wastes enters into the oceans through rivers. The first priority is to understand their source and beaching locations and to identify the potential connectivity between them at the regional and basin scale of the oceans. A simple Lagrangian assessment of the dispersion originating from 21 major rivers in Indonesia is addressed with the specific goal of identifying the regional and temporal distribution of “beaching particles” along the coastlines. The present study is based on the state-of-art ocean modeling and should be viewed as a first effort to establish the river connectivity implied in the ocean dispersion of marine debris and litter in Indonesia.