This study aimed to investigate the role of moderator Litigation risk on strongly associated between accounting quality and investment efficiency In Tehran stock exchange. For access to this aims 91 companies in Tehran stock exchange were active in period 2008-2013 are selected as sample.Methodological study based on objective and the method of data collection is descriptive. The results of this study indicated there are positive and meaningful relationship between accounting quality and investment efficiency In Tehran stock exchange and this correlation is 0.67. Also the results indicated in firms that’s Litigation risk is medium, relation between accounting quality and investment efficiency is more. In the other hand the role of moderator Litigation riskon associated between accounting quality and investment efficiency In Tehran stock exchange is accepted
