The role of the private sector in delivering agricultural extension and advisory services (AEAS) is of interest in relation to agrifood systems transformation in most developing countries. This study examined four private AEAS models that have emerged in the Kenyan agrifood sectors toward sustainable commercialisation with a focus on dairy and horticulture. The study assessed the design and operational features of the models and how they perform as agri-service enterprises, in contributing to farm improvements and financial sustainability of the focal firms’ core businesses. The findings highlight both similarities and differences in design and operationalization features of the models. The assessment shows mixed results in terms of their performance in delivery and uptake of extension services with some attention to being inclusive, revenue generation and financing, and benefits of extension to the focal firms’ core business and farmers. Stimulating market demand for the services and getting the financing model right are identified as the most critical success factors in establishing and scaling such models.