The critical role of knowledge management (KM) in achieving and sustaining a competitive advantage (CA) has been strongly emphasised in the extant literature. However, most previous studies were conceptually grounded and empirically examined in advanced, developed and newly industrialised countries and from a large company perspective. Meanwhile, little attempt has been made to address the relative importance of different factors constituting the organisational KM infrastructure capability in the context of Asian emerging, less developed countries such as Vietnam where a socialist market economy, a Confucian culture and a majority of small and medium sized enterprises currently exist. By adopting a resource-based theory of the firm with an extension of a knowledge-based perspective, this paper aims at developing and empirically validating a conceptual model of the relationships between KM infrastructure capability components and their impacts on a firmpsilas CA in Vietnam. The results of 148 surveyed respondents in the construction industry reconfirmed a general agreement found in the literature that a combined social and technological approach is ideal to take advantage of their significant positive correlations in improving organisational competitiveness. Moreover, in the Vietnamese-specific context, the study indicated that while culture is the most important issue affecting KM, integration with information technology may assist to overcome cultural barriers and provide a stronger contribution to a firmpsilas CA.