ICT adoption is among the important strategies used to maximize potentials of firms. However, the way ICT services are adopted and diffused within the firms tends to be affected by factors such as availability of reliable specialists in the area, governance issues, politics, available ICT infrastructure and financial capability. The variation of these factors makes it difficult for some firms to optimize the benefits of ICT and in some cases they fail to maintain the benefits which have already been experienced. Previous studies have discussed the factors of ICT adoption in specific technologies in the likes of e-commerce, internet and ERP systems in the forms and individual people. However, very few of them discussed the ongoing challenges faced by the firms in specific cultural and economic contexts. This research explores the factors which affect the adoption and diffusion of ICT in Tanzania based firms. This study involves deep discussions between key ICT managers in 13 organisations and other government officials. This research studies the challenges in the adoption context and diffusion contexts. Among others, this study revealed that most of problems associated with adoption of ICT products and services in the firms are based on the procurement processes.