The focus of the research is aimed at determining the most efficient models for information technologies` (IT) governance, including decision making, IT projects` portfolio management in the organizations. Research is based on the extensive literature review of the topic, qualitative (primary) – interviews with the representatives of the organizations, focus groups, and quantitative (secondary) surveys. The findings reveal different models used for IT governance and decision making and their impact on organizations` efficiency and effectiveness – how with the help of IT organizations increase their competitive advantage. It can be concluded that the most efficient models of IT governance are the ones where business leaders are fully engaged and have the final word for the IT decision making or IT top managers do it together with business top managers. It is recommended for the organizations to set up the most suitable IT governance models, so it supports reaching of their strategic goals.