The innovation systems approach is an analytical framework that is increasingly used to address agricultural innovation support services (ISSs). In the staple food production sector of Cameroon, a plurality of innovation support service providers (ISPs) co-exist, but ISSs are largely delivered within the framework of agricultural and rural development projects or programs. This paper aims to assess the impact of such governance mode on ISS delivery. Using a mixed research approach, empirical data have been collected focusing on the cassava innovation sub-sector in Southern region of Cameroon. ISPs at the local, regional and national levels (n=11) were first identified through literature review. Semi-structured questionnaires were administered to this first sample in order to create an ISP and projects database. A second semi-structured questionnaire was then administered to an enlarged group of ISP respondents (n=27) in order to characterize ISPs and ISSs, as well as to identify and measure the interactions among ISPs. Results indicate that public international and national ISPs dominate the system (high number of projects, ISSs and interactions with other ISPs), and that this leads to duplicity of certain types of services. The private sector and Farmer-Based Organizations (FBOs) are also present and offer rather complementary ISSs, but their number is comparatively lower. The lack of intermediary services to coordinate the overall ISS system, the rather low density level of ISP interactions and their informal quality give the impression of a fragmented ISS system. But, the interactions among ISPs are actually essentially very uneven. Although international public ISPs already interact well with FBOs, partnership strategies towards national public ISPs still need to be implemented. In turn, national public ISPs should also strengthen their links with these FBOs. Overall, ISSs delivered by national and international public ISPs, as well as by the FBO umbrella organi