This paper assessed the factors influencing employee retention in Tanzania's public and private sector workplaces. The purpose of the study was to reveal and assess the factors perceived by employees as forces influencing retention at the workplace in each sector and investigating employers' psychological factors and different methods used by the organizations in retaining their best employees in each sector. The study used semi-structured, closed and open ended questionnaires, Focus Group Discussions, Key informants as well as review of documents from various libraries and online resources. This study used a sample of 60 respondents drawn from ten (10) selected organizations .software Package for Statistical Science (SPSS) version 20.0 and excel. The study findings revealed that there is a high rate of turnover in Tanzania's work organizations and that those who stayed in the same organization were from public organizations particularly higher learning institutions. The study also revealed that, low salaries and benefits were the main reason for leaving. Furthermore, employer psychological factors including organizational justice and prestige were mentioned as influence to employee retention. Increasing salaries was mentioned to be the strategy used by the most companies in retaining their employees. The study, therefore, recommends that the selected organizations and others should conduct regular review of the remunerations, structure good retirement plans and foster a congenial or conducive work environment that provide and create opportunities for further development, continuous renewal and learning, and deepening of employee motivation to contribute stupendously to the organization's performance, workplace excellence, and competitive advantage.