Employee turnover is a vital element in the survival and success of an organization and should be considered when developing strategies and business plans to ensure a competent and skilled workforce that delivers the organizational objectives and goals. The departure of key employee can have a drastic impact on the efficiency of the organization. The Assessment of employee turnover and their effect on organizational efficiency at Keroka Technical Training Institute is a complex area of study. Numerous studies have been published about employee turnover and job satisfaction however there is a paucity of information in literature about the Assessment of employee turnover and its effect on organizational efficiency at Keroka Technical Training Institute. With rising globalization, accelerated use of technology and pressure to innovate and remain competitive in the Kenyan sector, it is becoming increasingly important for Keroka Technical Training Institute to attract and retain rich human capital. The study is guided by the following objectives; to determine the extent to which management styles contributes to employee turnover; to establish the role of work environment as a contributing factor to employee turnover and to evaluate the extent to which reward management contributes to employee turnover. The findings indicate that management styles, the work environment and reward management play a key role in employee turnover at Keroka Technical Training Institute. Employee turnover affects organizational efficiency by touching on all the four perspectives of the Balance Scorecard; customer, financial, internal Management process and learning and growth. The highlighted recommendation is that Keroka Technical Training Institute must regularly conduct employee-manager reviews and provide feedback, must align the working environment with the changing, dynamic and culturally diverse workplace, there is need to have employee friendly policies and procedures that provide an enabling environment that allows creativity and innovation. Finally, reward packages should be more favorable and in line with employee needs and the organization should establish modern retention strategies to enhance retention.