Human resource management (HRM) is still a new concept in Iran and there is significant research to be done, mainly because of the changes over the past two decades and the recent increase in the re-emergence of multinational companies (MNCs). An active area of academic debate is the degree to which HRM practices follow the multinational or local partners practice in international joint ventures (IJVs). The research suggests the significance of ownership structure of critical resources. The study also shows the importance of socio-cultural differences on the transferability of HR practices and whether these are MNC standardised or localised to the host country. Based on the information from the research findings, the main factors which influenced MNC standardisation or localisation of HRM practices were ownership and control of critical resources, the compatibility of national culture and socio-cultural differences, mutual trust and respect between partners and the compatibility of management styles of the IJV.