Biometric authentication has emerged as a promising technology to secure banking operations, reduce fraud, and enhance customer experience. However, the implementation of biometric authentication in the banking sector is not without challenges. This study aims to assess the key success factors for biometric authentication in the Kenyan banking sector in KCB Thika by exploring the factors that influence its adoption, implementation, and effectiveness. The research employs a quantitative research approach, consisting of a survey of banking customer and employees. The study identifies several key success factors for biometric authentication in the banking sector, including user acceptance, technical feasibility, regulatory compliance, cost effectiveness, system reliability, and scalability. The findings reveal that user acceptance is a critical factor for the successful implementation of biometric authentication in the banking sector. Customers' perceived ease of use, perceived usefulness, and trust in the technology influence their acceptance of biometric authentication. Technical feasibility, including accuracy, speed, and compatibility with existing systems, is also crucial for successful implementation. Moreover, regulatory compliance is a critical factor, given the sensitive nature of banking operations and the potential risks associated with biometric data. The study finds that cost-effectiveness and system reliability are key factors that influence the adoption and sustainability of biometric authentication in the banking sector. Scalability is also an essential factor to consider, as biometric authentication needs to accommodate a growing customer base and increasing transaction volumes. Overall, the study concludes that biometric authentication has the potential to enhance security and improve customer experience in the banking sector. However, its success depends on careful consideration of the factors that influence its adoption, implementation, and effectiveness.