In the recent days behavioral finance play the predominant role for the investment decision making in the field of finance. The paper assesses impact of demographic variables on behavioral biases of an investors in investment decision making. The purpose of the study to examine the influence of demographic variables such as, gender, income, age, education, occupation, investment expertise, investment knowledge on investor behavioral biases especially cognitive biases. The study uses descriptive research with a quantitative approach. On this basis the primary data analysis is conducted to know the impact of behavioral biases. Statistical tests were employed to determine the impact of demographic variables on behavioral biases such as, cognitive dissonance bias, representativeness bias, hindsight bias, conservatism bias, anchoring Bias, availability bias, mental accounting bias and illusion of control Bias. ANOVA and t-test were applied to study the effect of demographic variables on behavioral biases of an investors in investment decision making. The study focuses on the impact of demographic variables influence the behavioral biases of an investors during investment decisions.