This study set to carry out research on the adoption of e government among the medium business enterprises in Nairobi County. The need for the study was conceptualised due to the trend of research findings in most developing countries that point to failures in the implementation of e government, despite the government having put in place plans to implement e government in Kenya, the process has been slow and superficial and therefore the need for the study. The Objectives of the study was to find out the adoption level of medium Business enterprises, it also sought to find out the factors affecting adoption of e government while also trying to establish the challenges facing adoption of e government. It considers theoretical foundations from the Diffusion of Innovation Theory and Technology Acceptance Model to understand the adoption level of medium business enterprises in Nairobi County. The study employed descriptive research design by use of survey of medium business enterprises to portray their adoption characteristics in Nairobi County. It used quantitative method in gathering data from a sample of 50 respondents selected purposively. Analysis of the data was descriptive and involved frequencies and percentages. The findings revealed low adoption of Nairobi City County portal by the medium businesses in Nairobi. The research also revealed that various factors led to the low adoption of Nairobi City County portal, these factors include Compatibility, Complexity, Trialibility, Observability and Lack of knowledge and Trust in the system. The study proposed various recommendations based on the objectives, key among them include; publicity campaigns in order to create awareness of the e government innovation, Public/private partnership between NCC and commercial Cyber cafes on how to provide assistance to users seeking to acquire e government services. The other recommendations include the need for a system generated automatic change password process without going through an agent to avoid delays in access.