Evaluation of strategies in Kenya may be done either quantitatively or qualitatively. This is to ascertain whether the process of implementations will succeed in attaining the objectives or not. This study sought to investigate the implementation dynamics of strategic plans in secondary schools in Masaba north-sub county, Nyamira County, Kenya. The study used descriptive research design to get the information under investigation. The target population consisted of: 1 Sub county Education Officer (SCEO) and 31 Principals. The study used purposive sampling and simple random sampling. The research instruments used to collect data was questionnaires and Interview schedules. The findings of the study show that during the implementation of strategic plans school environment affect implementation of strategic plans through effective Institutional policies which reflect the picture of school needs, The Education policy makers would find this study useful in spearheading a campaign to foster a positive attitude among stakeholders who have the implementation dynamics of strategic plans in secondary schools, also to bring forth a practice where major players in schools adopt a willingness to work and bring changes in performance in all the departments in an institution to improve on strategic planning process.