The goal of this study is to examine the influence of certain behavioral biases namely overconfidence, loss aversion, mental accounting on women entrepreneurs’ investment decision accompanied with mediating role of risk tolerance. The research has employed PLS-SEM to empirically examine the formulated hypotheses. Additionally, IPMA analysis has also been implemented to know the comparative importance and performance of selected facets. The sample size includes 100 women entrepreneurs residing in Karachi, Pakistan. Convenience sampling technique is executed to gather data whereas a questionnaire is adopted as research instrument. The empirical findings suggested that overconfidence bias, mental accounting bias have a substantial positive influence on women entrepreneur investment decision whereas loss aversion is found to be statistically insignificant. However, the indirect impact of risk tolerance has been found to be statistically insignificant for the given biases and women entrepreneur investment decision whereas loss aversion, mental accounting found to have substantial direct influence on risk tolerance of women entrepreneurs. Through its conceptual framework, the research adds to the body of literature by providing valuable insights regarding women entrepreneurs’ behavioral perspective in relation with investment decision. The empirical evidence has determined the presence of irrationality involves in entrepreneurs’ investment decision; the findings will be helpful to understand the mechanism and causes that may lead to unidentified anomalies in start-up markets.