Gilded catfish (dorado) Brachyplatystoma rousseauxii is one of the most threatened Amazon fish species. Its complex life cycle is interrupted by hydroelectric dams that were built on the middle Madeira River. Despite this, the species seems to continue spawning in the Beni River, a tributary of the Madeira River. We conducted a spatial analysis that allowed us to identify aditional spawning sites in the Madeira basin. Hydrological and topographic information available at watershed level was used and a similarity analysis was performed to geographically locate potential spawning areas. Seventy sub-basins were identified that meet the same characteristics as the documented spawning area in Beni and might constitute 22 potential spawning areas for dorado. All identified zones correspond to >4th order tributaries with a direct origin in the Andes. The precise identification of these zones allows the planning of monitoring efforts using a citizen science approach to confirm the reproduction of dorado in the Madeira basin and will help generate information that may serve to prevent species extinction in this basin.