For more than two decades, knowledge management (KM) has been examined in the literature and considered a basic factor in business management. The purpose of this article is to explore the ability of knowledge management to achieve small and medium-sized enterprise (SME) innovation and business performance. Data analysis procedures of PLS-SEM was used to analyze the data based on responses from the owners of 903 companies in industry, construction, services, and trade in the Region of Murcia (Spain) through a self-directed survey. The results show that KM has a significant influence on innovation but the influence on the level of performance of SMEs is insignificant. However, training employees as part of KM showed no significant influence on innovation in SMEs. It is important for leaders and managers to have greater openness to changes in the implementation and proper execution of KM. This work contributes primarily to the development of the literature on knowledge management and its relationship with innovation and business performance.