Temporal employment has become a reality in the current labour market, however their impacts on employees, employer and institution effectiveness has not been well investigated. The study investigated the effects of temporal employment on effectiveness of workers in Secondary schools in Butula Sub-County in Kenya. The study provides both qualitative and quantitative aspects of effects of temporal employment on effectiveness of workers performance in Secondary schools. The study established that temporary employees work for long hours, are paid very little money and they can lose their jobs anytime. They also face the problem of lack of job security and almost all temporary employees wished to be employed permanently. The study therefore indicated that there is need for proper integration of temporal employees with regular employees for improved service delivery.