In today's investment world there is emphasis on the role of accounting information. Behavioral factors always play an important role in financial markets. All investors are not rational and their demand for riskiness of assets is influenced by their beliefs and feelings. Optimism, pessimism, self-confidence, ambiguity-aversion, etc. help changing the manner of decision-making process over time. So, this study aimed at investigating the role of accounting information on investors’ ambiguity-aversion in economic environment of Iran. For this purpose, information about 120 companies listed in Tehran Stock Exchange during the period 2013 to 2017 was collected and analyzed. Multivariate regression models were used to analyze the data. The results show that earnings announcement premium for companies with high level of ambiguity, is more than for companies with low level of ambiguity. As a result, investors respond asymmetrically to good and bad news, and this asymmetry decreases with increasing of ambiguity level.