Decision-making and investors’ behaviours are affected by various factors in Tehran Stock Exchange. Based on theoretical perspective, investors collect the key information of decision-making by the study of macro- and micro-levels of investment environments. To analyse the research data, path analysis and Linear Structural Relationships (LISREL) software are used. The results indicate that political factors with 62%, psychological factors with 53%, economic factors with 47% and internal factors with 31% are the most important factors that affect the stocks trading in Tehran Stock Exchange. Political and psychological factors not only have direct effect but also affect the investors’ financial decision-making indirectly (through ntended interest rate) 16 and 11%, respectively. The total effect of political and psychological factors on investors’ financial decision-making is 79 and 64%, respectively.