This study aims to identifying the reality of the big data management in the governmental institutions in Sultanate of Oman the sources of this data, the ways of dealing with it, factors affecting its management and its investment areas. The study was based on the qualitative descriptive approach through using the semi-structured interviews as a tool for data collection. This study covers governmental institutions in sultanate of Oman and National Center for Statistics & Information, the General Secretariat of the Supreme Council of Planning, and the Information Technology Authority is taken as a sample of this study. The study reached to a set of results: Omani governmental institutions are varied in their management of big data. One of the most significant models of big data initiatives was the e-census 2020 project that adopted by the National Center for Statistics & Information. Furthermore, the results showed a range of sources that governmental institutions depend on as main sources of big data, the most important includes: official administrative records, field and electronic surveys, geographic information systems and projects and electronic systems. Moreover, the study pointes that dealing with big data is done according to several mechanisms, such as: storing data, programs and applications used to process and analyze them, and data output after analysismoreover, the extent to which big Data is retained and updated. Finally, are number of supportive factors for big data management in Omani governmental institutions such as: the administrative and technical factors, as well as factors related to the nature of data. While the lack of readiness of some govemment institutions to share data, the lack of human resources, and the volume of data and the multiplicity of sources, are the challenges that affect the benefit of big data. The results of the study indicated that the study sample invested big data in strategic planning and decision making, understanding the needs of individuals and improving the services, as well as predicting future needs. The study concludes with a number of recommendations: First, finding a national plan to take advantage of big data in both public and private sectors, to produce a unified systems and methods for data analysis and processing, and utilizing big data in decision making and facilitating access to it. Second, raising of awareness and culture of the importance of big data among decision-makers and all members of the community, through organizing more conferences and symposiums, and sharing the interational experiences in big data systems and way of dealing with it in various sectors.