Information Technology Governance (ITG) is one of the most innovative practices through its provision of support for decision-makers in organisations. Interestingly, it has increasingly become a de facto strategy for organisations that are seeking to optimise their performance. ITG has emerged to support agencies in the integration of information technology (IT) infrastructures and the delivery of high-quality services. On the other hand, decision-making processes in public sector organisations can be multi-faceted and complex, and decision-makers play a major role in the adoption of innovation and technology in the government agencies. While formally adopting IT governance (ITG) has numerous reported benefits, many studies have shown that few organisations have adopted the ITG practice, particularly in the government sector. Therefore, this study attempts to identify and understand the dimensions that hinder ITG adoption and its successful use. The main objective of this research is to investigate and develop a theoretical model of the obstacles preventing formal ITG adoption, from both institutional and individual perspectives. Based on empirical evidence gathered via semi-structured interviews (n=32) with IT directors in government organisations as a qualitative inquiry, this study attempts to investigate institutional and individual dimensions that impact decision making for the adoption of ITG in the context of the public sector in development countries such as Oman. Furthermore, this study focuses on combining institutional and individual perspectives to explain how individuals can make decisions in response to institutional impacts via the integration of theories such as Institutional Theory and the Theory of Planned Behaviour (TPB). It also explores the key dimensions that influence decision-making in the public sector concerning the adoption of ITG. The findings of this study illustrate and analyse the institutional and individual dimensions that impact on decisions for the adoption of ITG and contribute to the body of knowledge by highlighting the dimensions impacting decision-making for adopting ITG in public sector organisations. In doing so, this study contributes to better understand the applicability of integrating both TPB and IS theories to explore and develop a model of ITG adoption in the public sector organization and advances the scholarship by developing a more holistic model. This adoption has benefits such as reaching organisations' strategic goals, improving performance and conferring other competitive advantages. As a final point, this study advises accelerating the adoption of ITG to increase the efficiency, productivity and transparency of government work as well as to make available integrated smart electronic services. Further studies on the adoption of ITG in the public sector in different contexts, or comparative research, may help to develop a deep understanding of the value of ITG innovation in government organisations to enable evaluation of its significance in enhancing e-government.