Despite the market forces the co-operatives societies in Kenya have continued to flourish in membership and size. In the current open global economy, saving and credit co-operatives (SACCOs) just like other financial institutions in the private sector must endeavour to be effective in offering proficient services in order to attract and maintain their members. This has forced SACCOs to develop strategic plans as a roadmap to ensure sustained SACCO performance. This study aimed to establish the effect of implementation of strategic plans on SACCOs’ performance in Nyeri County, Kenya. Particularly, the study examined effect of leadership style, organisational structure, human resource management, and information communication technology on performance of SACCOs in Nyeri County, Kenya. The study employed explanatory research design. The target population for this study comprised of 36 SACCOs in Nyeri County. Due the size of target population, a census was conducted where all SACCOs were included in the study. Structured questionnaires were used for primary data collection. Descriptive, inferential analysis was used to analyse quantitative data while content analysis was used to analyse qualitative data. The study found that democratic leadership endeavoured to promote team spirit among the workers as well as encouraging team work while empowering individual employees. The study found that SACCOs’ management slightly involved junior teams in development of strategic plans. The study also found that human resource department in most SACCOs recognised and conducted rapid promotions for exemplary performance among the SACCOs employees. The study found that majority of the SACCOs had adopted and enhanced ICT culture across all departments in their SACCOs. However, the study found that majority of the SACCOs marketed their services to the local Kenyan market. The study concludes that quality of human resource management is important for success of SACCOs. The study concludes that adoption of appropriate Information Communication Technology not only promotes internal efficiency but also enhances external competitiveness by providing SACCOs with a platform to market their service to the global market. The study recommends that the SACCOs regulatory body should develop a guideline for SACCOs on organisation structure and help them implement over a period. The SACCOs regulatory body should enforce recruitment of qualified human resource management to ensure the functions of the HR are not overlooked.