Broadband is viewed as a most significant evolutionary technology that is shaping modern society and transforming the traditional information and communications technology (ICT). Investigating broadband diffusion (adoption, usage and impact) has become an evolving research area in developed and developing countries. However, despite the attention given to simulating the diffusion of broadband in developing countries, little is known about the key factors that impact Omani households and individuals towards its adoption as well as its usage and impact. This research attempts to address this issue by providing a deeper understanding and more holistic analysis of the key factors that impact fixed and mobile broadband adoption. Besides, to understand broadband usage and its impact upon households and individual users in Oman. This study employed a mixed-method approach using qualitative interview) and quantitative (questionnaire). Through semi-structured interviews, this study explored the current situation of broadband development in Oman while questionnaire survey was employed to investigate the diffusion of both fixed and mobile broadband in Oman by households (a sample of 295) and individuals (a sample of 652) respectively. The findings demonstrated that fixed broadband adoption can be explained by behavioural intention (i.e. utilitarian outcomes, perceived cost), behavioural intention towards shifting to fibre broadband (i.e. utilitarian outcomes, service quality, perceived cost) and adoption behaviour (i.e. facilitating condition resources). While, mobile broadband adoption can be explained by behavioural intention (i.e. primary influences, perceived ease of use, perceived cost and facilitating condition resources) and adoption behaviour (1.e. hedonic outcomes, service quality and facilitating condition resources). Concerning usage behaviour in terms of the rate of use and variety of use, the findings indicate that both fixed and mobile broadband users can be classified as experimental, intense or limited users. Among fixed broadband users the emphasis is on experimental users, while among mobile broadband users the emphasis is on experimental and intense users in relation to entertainment-based services. It was also found that broadband usage significantly affects fixed broadband users with regard to interest in future broadband oriented technologies, while mobile broadband users expressed partial impact in terms of satisfaction with broadband technology and lifestyle. The findings of the present study extended the growing body of research on broadband adoption by employing a broadband ecosystem and broadband adoption model to gain a comprehensive understanding of the adoption issues in Oman. It adds also to the existing literature on broadband diffusion in developing countries in general and GCC countries in particular. Additionally, it provides prescriptive value for practitioners seeking to realise efficient and effective methods to develop broadband in Oman and encourage the demand. Keywords: Broadband, Fixed Broadband, Mobile Broadband, Adoption. Diffusion, Policy, Supply Side, Demand Side, Penetration, Oman