Purpose: The Effect of working capital management on the firm's profitability in the companies listed on the Tehran stock exchange.
Methodology: The sample of the study consisted of 125 companies that have between 2014 to 2019 were studied. In this study, the variable "net income before deducting interest and taxes to total assets" as a measure of the profitability of the variables, the period of collection of receivables, inventory turnover period as capital management criteria in circulation in variables, firm size, sales growth, the ratio of current assets to current liabilities ratio of financial debt to total assets and operating profit were used as the control variable.
Findings: The result of this study showed that there is a significant inverse relationship between the profitability of companies with receivables collection period and between the profitability of companies with inventory turnover period significant relationship was not found. In other words, managers can reduce the period with the debt collection company to stay within reasonable limits and increase profitability.
Originality/Value: it is expected that companies by used proper management of working capital take steps to increase the value of the company and thus increase the wealth of its shareholders.