The study reports the experience of Citizen Science, considering the use of the “ICTIO” application by fishermen (developed by the Wildlife Conservation Society - WCS e Cornell Lab of Ornithology and the partners of Citizen Science for Amazonia) in the Madeira basin as a tool to help fill data gaps on small scale fisheries in the Amazon, and to support the fish conservation. In the Madeira basin (Rondônia) was developed by ECOPORÉ ONG with the Laboratory of Ichthyology and Fishing (Federal University of Rondônia) at fishing communities and Porto Velho Fishing Market, Rondônia. The project was initially presented and discussed how ICTIO could answer fishermen and researcher questions, training for the use of the application and continuous monitoring. The data collected from 2018 to 2021, were compared with historical data from the basin, to see patterns in catches of commercial fish, especially migratory fish. The results allowed to answer some of the fisher questions, validating ICTIO as a powerful tool in obtaining information on fisheries changes that can support fisheries conservation and management. In addition, is an important opportunity to create and share knowledge between traditional scientists and citizen scientists.