Over the years, extension agents are seen as officers who provide inputs and advice farmers on the best agricultural practices to give them high yield, however agro-dealers compliment these services. The paper assessed the effectiveness of agro-dealers’ services on farmers’ access to agricultural inputs in South-West Nigeria. Specifically, the study examined the services rendered by agro-dealers, their challenges and the level effectiveness of agro-dealers’ services on farmers’ access to agricultural inputs in Ekiti, Osun and Oyo States. Multistage and proportion sampling procedures were used to select 360 farmers and 122 agro-dealers. Agro- dealers provide advisory (x̅ =2.30), linkage (x̅ =1.47) and vaccination services (x̅ =1.24) to farmers. ANOVA results indicated that a significant difference (F= 14.065, F= 24.873 and F= 16.623) exists between the effectiveness of agro-dealers’ services on farmer’s access to seeds, herbicide and Equipment in Ekiti, Osun and Oyo States. However, fertiliser with F= 2.740 was non-significant. The study concludes that agro-dealers perform effectively to farmers’ access to seeds, herbicides and equipment which were in high demand by the farmers while they stock fewer fertilisers.