This chapter introduces electronic commerce or e-commerce (EC) in the small and medium enterprises (SMEs) in Brunei Darussalam which has dramatically altered the way businesses are conducted. The advent of EC has changed the trading and buying pattern of consumers behavior. The present research investigates 71% of SMEs EC adoption and study the determinant factors. Several organizational factors such as nature, size, and type of business along with organizational culture and management support were studied. The study also includes technological factors such as perceived benefits and task variety and one environmental factor of government role and support towards EC adoption. This study has concluded on the basis of various statistical tests that there exists a significant difference of EC adoption among SMEs. For small enterprises task variety and favorable top management support remain significant. Whereas, for medium-sized enterprises the study support the organizational, environmental and technological variables toward EC adoption. This is mainly due to the fact that medium-sized enterprises are better resource-driven as compared to the small business. This study also discusses the reasons why 29% of the organizations did not adopt EC. The most common reasons of non-adopters include: high cost of Internet service provider, a major time wasting activity for the staff, and lack of overall staff computer literacy. Based upon our findings, some recommendations were made to the policy makers and relevant authorities for devising and implementing a strategic plan to enhance the EC adoption among SMEs.