This study investigates the impact of behavioral biases on investment decisions of Nepalese investors, focusing on overconfidence, representativeness, anchoring, regret aversion, and herding biases. The research employs a linear regression model using data from 379 investors, revealing that overconfidence, anchoring, and regret aversion significantly influence investment decisions, while representativeness and herding have lesser or no impact. The findings highlight the significant role of behavioral biases in shaping individual investment choices in the Nepalese financial market. The study underscores the importance of addressing these biases for informed decision-making, financial stability, and market development. The results indicate that overconfidence bias has a positive and significant effect on investment decisions, while anchoring bias also shows a positive and significant influence. Regret aversion bias, although positive, has a weaker effect. Herding bias, though present, does not show statistical significance. The study contributes to the understanding of behavioral biases in investment decisions, emphasizing the need for awareness and mitigation of these biases among investors, financial advisors, and policymakers. The research provides insights into the complex interplay of behavioral biases and investment decisions, offering a foundation for future studies and targeted interventions.This study investigates the impact of behavioral biases on investment decisions of Nepalese investors, focusing on overconfidence, representativeness, anchoring, regret aversion, and herding biases. The research employs a linear regression model using data from 379 investors, revealing that overconfidence, anchoring, and regret aversion significantly influence investment decisions, while representativeness and herding have lesser or no impact. The findings highlight the significant role of behavioral biases in shaping individual investment choices in the Nepalese financial market. The study underscores the importance of addressing these biases for informed decision-making, financial stability, and market development. The results indicate that overconfidence bias has a positive and significant effect on investment decisions, while anchoring bias also shows a positive and significant influence. Regret aversion bias, although positive, has a weaker effect. Herding bias, though present, does not show statistical significance. The study contributes to the understanding of behavioral biases in investment decisions, emphasizing the need for awareness and mitigation of these biases among investors, financial advisors, and policymakers. The research provides insights into the complex interplay of behavioral biases and investment decisions, offering a foundation for future studies and targeted interventions.