Tacit knowledge is a strategic resource that can unlock human potential to the fullest and enable the creation of new knowledge if employees share their knowledge among themselves. It is believed to be significant for the performance of the academics whose job nowadays goes beyond teaching and research to administration, consultation, and commercialisation. By taking an individual and ethical perspectives, our study emphasised on Islamic work ethics and autonomous motivation as critical human elements to improve and promote tacit knowledge sharing (TKS) among the academics. Underpinned by SelfDetermination Theory (SDT) of motivation and Islamic code of conducts, this study hypothesized a positive relationship between Islamic Work Ethics and TKS, and a mediation effect of autonomous motivation in the relationship between Islamic Work Ethics and TKS. Questionnaire surveys were distributed to the fulltime Muslim academics working in five research-based universities in Malaysia. PLS statistical techniques was utilised in analysing the questionnaire collected from 315 academics. The results of this study substantiate the positive link between Islamic Work Ethics and TKS, and reveal that autonomous motivation partially mediates this relationship. Theoretically, the present study contributes to knowledge by providing support for the importance of SDT of motivation as a mechanism in explaining the relationship between Islamic Work Ethics and TKS. Practically, this study suggests to the management of university and practitioners that maximum benefits from tacit knowledge sharing can be realised by fostering Islamicbased ethical values, and giving autonomy to the academics to increase work motivation.