Knowledge Management is a young discipline that nowadays it is important for many kinds of organizations. For software development organizations (SDO) the effective use of knowledge is a fundamental aspect to improve their processes and obtain sustainable competitive advantages. In this sense, this paper presents a critical review about how the knowledge management has been included in the processes established/ defined by several Software Process Reference Models. For this study, five software process reference models, broadly used in Latin-American countries, were selected: the standard ISO/IEC 12207, the Capability Maturity Model Integration for Development (CMMI-DEV), the Brazilian Model for Software Process Improvement (MPS-BR), the Mexican Software Process Model (MoProSoft), and the Latin-American software process improvement model for small and medium enterprises (COMPETISOFT). To obtain the review, the follow three stages were defined: 1) selection of process reference model to analyze; 2) analysis of each process proposed in process reference models, in order to identify the aspects related to knowledge management; 3) mapping the knowledge management aspects in relation to the taxonomy of knowledge management schools proposed by Earl and the classification of organizational capabilities linked to knowledge management, proposed by Gold, Malhotra and Segars. The findings of this study show that in all models there are elements of knowledge management processes, and there are two models, MoProSoft and Competisoft, that have a process area named Knowledge Management. Nevertheless, the knowledge management aspects included in these models is grounded in statements from Earl's systems and engineering schools. Likewise, in terms of Gold's knowledge management capabilities, the technology, knowledge acquisition and knowledge conversion capabilities are broadly covered but elements for others capabilities are not included in these reference models. This work constitutes an important reference for research and practice because presents a synthesis of the knowledge management topics included in software process reference models and helps practitioners, from software development organization, to identify the foundations and the options to implement knowledge management initiatives within their organizations. Likewise, this study helps researchers to identify trends and topics to formulate new research projects about include the different "flavors" of knowledge management in software process reference models or to develop a knowledge management process reference model relevant for software development organizations.