This study investigates the effects of training on behavioral changes and overall performance at both the employee and organizational levels within the private banking sector of Bangladesh. Using the Theory of Planned Behavior (TPB) and Goal-Setting Theory (GST) as the theoretical framework, the research explores the underexamined third and fourth levels of Kirkpatrick's training evaluation model, focusing specifically on behavioral outcomes and their subsequent influence on performance. Data collected from employees through structured questionnaires were analyzed using the Paired sample t-test. Findings reveal that training positively impacts employee behavior and enhances individual and organizational performance, particularly in effective teamwork, job satisfaction, work quality, task efficiency, and retaining existing clients while attracting new ones. This study represents one of the first empirical investigations in the banking sector of Bangladesh to link behavioral change evaluation to performance outcomes evaluation following training interventions. The research provides valuable insights for policymakers and organizational leaders, emphasizing the need for comprehensive training programs to promote skill development and behavioral and performance improvements. Future research should incorporate a larger sample size, adopt a longitudinal design, use advanced statistical methods like structural equation modeling (SEM), and investigate moderating variables to better understand the complex relationships between training interventions, employee behavior, and performance outcomes.