Multiples method used in evaluating companies started to gain increasingly more credibility to the specialists compared to the traditional business evaluation methods. There are many studies, both theoretical and empirical, that focus on this topic especially on the accuracy of determining multiples and choosing the peer group (comparable company group selection). The objective of this research is to evaluate the shares listed on the Bucharest Stock Exchange by using multiples method, more precise to determine the degree of underestimation or overrating of shares using PER analysis. The research methodology is a constructivist one, the orientation being one explanatory. Methods and techniques used are quantitative analysis, ARIMA model, correlation and regression. For data collection we used the information from different authorized institutes such as Bucharest Stock Exchange Market, National Agency of Fiscal Administration and the National Institute of Statistics. Research findings can be summarized as follows: calculating growing rate by using the information listed in the balance sheet will lead to an underestimate of the shares, PER lead to an overvaluation of shares, compound average and regression analysis provides the most plausible method of determine the degree of underestimation or overrating of shares for listed companies. The study contributes to the development of company valuation method using multiples.