The main purpose of this paper was to analyze and evaluate the influence of behavioral factors on private investors’ investment decision in PLCs at Bahir Dar city. The researcher, based on the post positivism world view, used quantitative type of research approach and explanatory type of research design. The researcher used the primary data source to collect the necessary data for the analyzing the descriptive and the inferential statistics. In order to select the representative sample that best infer the entire population, the researcher used simple random sampling technique of the probability sampling method. The researcher studied and evaluated particularly to determine the extent of behavioral factors predictor variables (Representative bias; anchoring bias; availability bias; overconfidence bias; loss aversion bias; regret aversion bias; mental accounting bias; market information; price change; imitation) influence on the response variable private investors’ investment decision. The researcher used SPSS version 20 for data encoding, coding, editing and for depicting the figure and StataSE 14 for tests and regression analyses. In order to test the reliability of the questionnaire for each respective predictor variable and over all reliability test, the researcher used Cronbach’s alpha test, hence, in the test, he found that as it is reliable since the cronbach’s alpha value is greater than the threshold value 0.7 which is appropriate and advisable for serving as a threshold. Moreover, chi-square test of association was employed to check whether there is an association between the response variable investment decision and the predictor variables explanatory variables. In that, based on the result, the researcher found that loss aversion bias, availability bias, anchoring bias, and price change have a statistically significant influence on the investment decisions of the private investors at PLC in case of Bahir Dar city. The researcher also used multicollinearity test to know the interdependence between the predictor variables, behavioral factors, each other. As a result of the test, he found that with the exception of some predictor variables which have either a weak positive or negative interdependence between each other, all other most predictor variables, behavioral factors, have no interdependence between each other.