Higher quality information is expected to have a favorable effect on investors' expectations of expected return (capital cost). Capital cost is one of the effective variables in decision making models and is defined as the expected return of shareholders. The purpose of this study was to investigate the relationship between information disclosure, company growth and cost of capital in companies listed on the Tehran Stock Exchange. This research has been done by descriptive-correlation method and is of applied research type. The statistical population of the research consists of all companies listed on the Tehran Stock Exchange during the years 1391 to 1395 that 100 companies have been active in the stock market during the entire period of research and have been studied. Research data were extracted from corporate financial statements and analyzed using regression models using combined data method. Findings showed that there is a positive and significant relationship between capital expenditure and company growth. The results also show that there is no significant relationship between disclosure and the cost of capital.