Today, Oil and Gas industry are at a cross road of overcoming their knowledge deficit by implementing knowledge management system (KMS). However, at this stage, many organizations are still facing with some difficulties and challenges related to its adoption. As decision making is one of the factors for individual in organizations to adopt the system. This study seeks to identify the types of innovation decision according to Rogers' (1995) innovation diffusion theory. The company of this case study faces with KMS adoption which only 15 active users at present. The identified innovation decision from the result could prove useful in understanding the employees' decision making and also give the possibility to help company reaches its KMS goals. © 2011 IEEE.