This study assesses the implementation and progress of the County Integrated Development Plan (CIDP) in Kisii County, Kenya, a key policy framework for fostering sustainable development at the county level. The CIDP serves as a blueprint for the allocation of resources and planning of various development projects, focusing on sectors such as infrastructure, health, education, agriculture, and economic growth. This research examines how effectively the Kisii County Government has implemented the CIDP, identifying key challenges, successes, and gaps in achieving the intended development goals. Data were collected through surveys, interviews with county officials, and review of official documents and reports. The findings highlight varying levels of success across different sectors, with notable progress in infrastructure development and agriculture but challenges in healthcare and education delivery. Resource constraints, inadequate stakeholder involvement, and limited monitoring mechanisms were identified as significant barriers to effective implementation. The study recommends strengthening interdepartmental coordination, enhancing public participation, and improving monitoring and evaluation frameworks to ensure the successful realization of CIDP objectives. The findings provide valuable insights for policymakers, county planners, and development stakeholders aiming to improve the effectiveness of CIDP implementation in Kisii County and other counties in Kenya.