Kenyan banks have limited infrastructure for reaching out to customers. The National Financial Access Survey of 2009 shows that 32% of Kenya's bankable population remains totally outside the orbit of financial services and many more being served by the informal financial system. This has necessitated the introduction of agent banking. However, empirical studies on agent banking adoption and success factors are lacking. Subsequently, the primary objective of this study was to examine the factors influencing the success and growth of agent banking business in Mombasa County in Kenya. The following relationships were found to significantly influence agency banking growth: relative advantage, complexity, perceived usefulness; compatibility; perceived low costs, start-up capital; service provider support; service quality; availability; integrity; & confidentiality. Based on these findings, it was recommended that the following measures should be implemented: market expansion, agent training; agent incentive programs; agent monitoring; consumer information campaign; competitive pricing; liquidity management; contracting management companies; and provision of financial support initiative