Strategic planning is one of the most important determinants of organizational success since it influences the work performance. Effective strategic planning leads to success while, on the other hand, poor planning will occasion organizational failure. There are forty seven Counties in Kenya and Nyandarua County is one of them. Nyandarua County is one of the Counties that have so far developed a County Integrated Development Plan. Though development of CIDP is very sound idea its implementation has remained a big challenge.

This is authenticated further by the Auditor General‟s recent report on County governments‟ level of absorption of development funds report of (July,2015) where Nyandarua County was ranked last (47th) in terms of development funds absorption. The study sought to examine the factors that affect the implementation of Nyandarua’s CIDP. The study was guided by four themes leadership, resource allocation, organizational culture, and stakeholders’ influence that attempted to address implementation of CIDP. The study adopted descriptive research design. The target population constituted one hundred and thirty one members who included: members of county assembly, administrative and management staff (both top and lower cadre staffs) and opinion leaders who are living in Nyandarua County respectively. A stratified random sampling method was adopted. The study employed a structured questionnaire as research instruments to collect primary data. The questionnaire was pilot tested prior to collection of data for the main study. The Statistical Package for Social Sciences tool facilitated data processing and analysis. Data was analyzed using frequencies, percentages, regression and chi-square. The study established that resource allocation; organization culture and stakeholder influence had a positive and significant effect on the CIDP implementation. On the other hand, leadership or management style was found to have marginal influence on the CIDP implementation. The study encountered a number of constraints. For instance, some targeted respondents could not be reached due to their busy schedules, these included opinion leaders and MCAs. Time was also a limited as the research was to be done within the stipulated academic calendar. Accessibility of various sub counties was a challenge due to poor road network which has not been fully addressed. Being a research on county performance getting information from the county staff who were part of the population was not easy hence not many of them were willing to contribute fully or wanted to be seen filling the questionnaire less they be branded traitor. Another limitation was finance as the researcher doubled as a parent as well as student. To overcome all those challenges, the researchers dispensed the questionnaires personally and also went for them to beat the available time lines. Used the most widely acclaimed reliability test the Cronbach alpha to test reliability. It was, therefore, concluded that resources allocated to CIDP implementation be increased, have a unique progressive organization culture and involve pertinent stakeholders in CIPD implementation. The study recommended that Nyandarua County Government to allocate adequate resources to CIDP implementation and all relevant stakeholders should be involved in the implementation of CIDP.