Plastic pollution in an aquatic ecosystem may negatively impact ecology, aquatic species, and causes economic damage. Rivers provide an excellent opportunity for intercepting plastic pollution before it reaches the ocean. The aim of this study is to identify and quantify the number of plastic debris in the Citarum River. Plastic debris was collected from April to August 2021 at three sampling sites based on the stream location, i.e. upstream, midstream, downstream, using a framed pocket net with 1cm-mesh size as a sampler with the dimension of 2x1x3 meter that was installed at two transversal locations of the river. Observation was conducted three times a day, morning, noon, and afternoon each with 15-30 minutes duration. The methods applied include plastic debris separation, enumeration, classification, volume estimation, and weighting. Type of plastics that are commonly found in high number of items are plastic bags, clear plastic bags, and plastic packaging. The highest volume of plastic debris was found in the upstream part of the Citarum River compared to midstream and downstream. The existing reservoirs act as a trap for plastic debris and all riverine debris of the Citarum River. The plastic debris tends to be higher in the morning than noon or afternoon.