This study sought to investigate the influence of employee engagement on performance of research and training state corporations in Kenya. Specifically, the study sought to: determine the effect of traits, psychological state and behavioural engagements on performance of research and training state corporations in Kenya; to determine the moderating effect of demographic characteristics and the mediating effect of organisational commitment on the relationship between employee engagement and performance of research and training state corporations in Kenya. The study was anchored on resource based view and stakeholder theories and supplemented by social exchange, expectancy and work adjustment theories