This chapter introduces the impacts of knowledge management (KM) and organizational memory (OM) on strategic decision making. Close consideration and treatment of OM as part of a KM strategy are suggested as a central issue to the effectiveness of strategic decision making. This chapter uses the modified version of McLean’s Information System (IS) Success Model by Jennex and Olfman (2002) as a lens to examine the impact of knowledge strategy and technological resources, along with the impact of individuals and members from wider organizational context on decision-making processes. These components are then analyzed within Galliers’ (2002) IS Strategy Framework of emergent and deliberate strategizing. Furthermore, this chapter highlights the intermingled approaches to organizational KM practices that are due to the contextual nature of knowledge and the human need for social interaction. Results from our exploratory and continuing longitudinal study have clearly shown the significance of culture and human-driven knowledge requirements along side the use of an ERP system as part of an OMS. The authors account for the intersubjectivity of the concept and claim that organizations relying on acquired knowledge from past experiences on average make higher-quality decisions on business strategies for better future performance.