Abstract: The aim of this study was to assess the effects of staff motivation on the performance of employees at the public universities in Kenya. Specifically the study seeks to find out the effect of motivation stress factors on the performance of employees in public universities in Kenya. The study employed a cross-sectional evaluation survey approach. This used both qualitative and quantitative methods in the selection of the participants and collection of data. Cluster sampling was employed to select 384 respondents. Data collection instruments included interviews, questionnaires and document reviews. The collected data was captured in MS Excel and analyzed using SPSS version 24 (Statistical Package for Social Scientists). Linear regression analysis and Pearson’s correlation coefficient were run to determine relationship between stress factors and workers performance. The analyzed data was presented in suitable graphs, charts and tables. By correlating the determinants of stress with performance, the study found out that the determinants of stress include movement, motivation, workers relationships, management and working facilities. The study found a significant relationship (F (3,342) =57.717, p<0.05) between Motivation and Management and employee performance. The nature of the relationship was found to be positive in the sense that unit increase in Worker’s relationship, Worker’s movement, Workplace facilities and Management leads to an increase in Employee performance as demonstrated by the equation: Employee performance= 2.286+.096 Management+ .277 Motivation