Globalization and the changes in the funding policies at Public Higher Education Institutions -PHEI-, such as decreasing the state economic contribution funds and strategies focused to finance the demand are some of the factors that affect the sustainability of PHEIs. This situation requires the PHEI to manage the resources efficiently and to generate their own resources, reducing dependency on the state. Incorporating knowledge management in the financial management of PHEI contributes to the sustainability of such institutions in the sense that leverages the existing knowledge in the organization to reduce costs, to reduce rework and to identify patterns of useful behavior for decision-making, its help to improve organizational performance. However, there isn't a framework in the literature reviewed that guides the process of incorporating knowledge management for sustainable financial management in PHEI. This paper presents the theoretical principles based on the approach of soft systems thinking that should have a framework that seeks to incorporate the knowledge management into sustainable financial management in PHEI. This research is developed under in the SUMA project - Towards Sustainable Financial Management of Universities in Latin America, project funded by the European Commission through the ALFA III program. This project is intended as a starting point for future research on how by managing knowledge can contribute to the financial sustainability of public higher education institutions. This paper is organized as follows: first, it presents the theoretical concepts of knowledge management and its effect on financial performance, secondly it exposes the sustainability problem at PHEI and shows how the knowledge management may contribute to the sustainability in these institutions, and finally it presents the conclusions and references. The results of this study provides a basis for future research focused on the development of frameworks, models and methodologies to relate the knowledge management with the financial performance in the organizations.