In recent years, project management in consulting firms has grown due to greater demands for goods and services. However, this growth has meant that due to inefficiencies in the management, delays in project delivery times are generated. In addition, the same situation occurs for performance of personnel’s competences, as well as in defining the scope of the project. Therefore, this article proposes a model for the application of Project Management Body of Knowledge (PMBOK) based on knowledge management, which consists of the following areas: stakeholder management, risk management, cost management, time management, human resources management, quality management, integration management, and scope management. To show the ease of use of this model, a case study was conducted in an engineering consulting firm. The results of the application of the model were successful: the delay in project delivery times was reduced by 70% and the risks that may exist during execution were reduced by 67%. In addition, the company highlighted the success of the application of knowledge management because it improved the interaction and skills of staff by facilitating the implementation of the model.