This study drives at exposing the impact of accounting disclosure of environmental costs on quality of financial statements and its importance in rationalizing investment and funding decisions. The study administers a field study on a sample of (6) cement industry establishments in Egypt including accountants, auditors, environmental officials, investments officials, and financial managers in addition to a sample of teaching staff members in Egyptian universities, a sample of financial mediators in the stock exchange, and purposed sample of banks employees, and external auditors who are issuing reports and financial statements. The researcher has designed an investigation form to be distributed randomly on (700) respondents to be analyzed using appropriate statistical approaches for testing the relationships among variables. Results indicate the following: The first hypothesis: There is a significant statistical effect and relationship between accounting disclosure of environmental costs in financial reports and statements of cement companies enrolled in the stock market and quality of these financial reports and statements. The second hypothesis: There are significant statistical differences between quality of financial reports and statements of cement companies enrolled in the stock market and rationalization of investment and funding decision. The third hypothesis: There are significant statistical differences between accounting disclosure of environmental costs in financial reports and statements of cement companies enrolled in the stock market and rationalization of investment and funding decision.