In this paper, a methodology to evaluate the repowering of small hydroelectric power plants is proposed. This methodology considers the technical and economic viability of the project. The methodology includes an analysis of the current state of elements of the power plant, such as electromechanical equipment and existing infrastructure. The technical analysis includes the hydrological study, which allows determining the appropriate equipment based on the water flow. On the other hand, financial analysis provides a valuable tool to determine the viability of repowering. The case study is El Amarillo power plant in Portovelo, Ecuador, it is a small hydroelectric power plant, currently abandoned. The modernization of the power plant based on current technology allows the electricity generation from renewable resources, contributing to local development and the reduction of CO2 emissions with an installed power of approximately 3.3MW.