This paper investigates the effect of FDI on performance of manufacturing firms in Kenya. Little is documented about the link between FDI variables of capital flow, advanced production technology, marketing expertise and management know-how and performance of firms. The study’s sought to establish the effect of each individual FDI variables on firm’s performance. It also sought to established the overall effect of the performance manufacturing firms in Kenya. The population of study comprised 100 companies registered with Kenya Association Manufacturing as at the time of data collection in 2019 and that had over 10 percent foreign ownership. The respondents were the CEOs of organization. The study used a structured questionnaire to collect primary data. Descriptive and inferential statistics were both used to analyze the data. Data was pretested for normality, linearity, multicollinearity, autocorrelation and homoscedasticity and the data found to meet most of these preconditions. The Pearson correlation analysis was employed to discern not only the strength but also the direction of the interrelationships involving the variables. The researcher tested the effect of the components of FDI on performance of manufacturing firms. The study developed one hypothesis and four sub hypothesis. The results revealed that there was a statistically significant relationship between FDI and firm performance. This imply that to achieve better firm performance, the government need to come up with policies geared to attracting more FDI into the key sectors of the economy. Keywords: Foreign Direct Investment, Firm Performance, Capital Flow, Advanced Production Technology, Marketing Expertise, Management Knowhow.