Purpose This paper aims to investigate the motivational drivers for knowledge sharing (KS) through the application of mobile social networking (MSN) and their influence on employee productivity in the Malaysian construction industry. Design/methodology/approach The data was collected by distributing a self-administered questionnaire among employees working in the construction industry. A total of 250 questionnaires were collected and analysed using partial least squares structural equation modeling. This study used a variety of analysis methodologies including correlation analysis, reliability and validity testing, as well as a structural model in evaluating the relationships between KS, motivational factors and influence on productivity. Findings The empirical results of this study reveal that utilitarian motivation is positively related to internal and external KS. Similarly, internal and external KS have a positive influence on productivity, while internal and external hedonic motivation does not show any significant relationship with productivity. Research limitations/implications Considering the paucity of evidence regarding the determinants of KS motivational drives on employee productivity in the Malaysian construction industry, this study enriches the social cognitive theory-based literature on KS. Practical implications This study provides some insights to the players in the construction industry in implementing the most appropriate KS promotion strategies that could potentially influence employee productivity. Organisations in the construction industry that place great emphasis on utilitarian motivation including competency, reward and incentives are more likely to have a better influence on KS and, in turn, positively impact employee productivity. Originality/value This study meaningfully contributes to enhancing the understanding of the motivational drivers for sharing knowledge on MSN and its influence on productivity. The findings of this study potentially assist construction practitioners in developing a holistic blueprint for managing their KS towards improving the overall productivity of their employees.