This study examines the level of Environmental Disclosures by the companies listed in Colombo Stock Exchange (CSE) in Sri Lanka. The study further examines the association between some specific attributes of the companies and the level of Environmental Disclosures. For this purposes, a sample of 36 companies listed in Colombo Stock Exchange under Manufacturing Sector were selected. The level of Environmental Disclosure by each company is measured using Environmental Disclosure Index (EDI). EDI consists of 19 items of disclosure under four categories. Further, content analysis is used to analyze the level of Environmental Disclosure. The greatest score of 3 is awarded if the item related to Environmental Disclosure Index is disclosed quantitatively and specifically. A score of 2 is assigned to non-quantitative but specific information and score of 1 is given to general qualitative information. The association between companies-specific attributes and level of Environmental Disclosure is examined using Ordinary Least Squire Regression Model. The calculated EDI reveals that the level of Environmental Disclosure by Sri Lankan manufacturing companies is at a very low level. Further, the regression results show that the level of Environmental Disclosure is significantly associated with Environment Concern (EC) and ISO14001 certification (ISO). It is also found that the Shareholder Power (SP), Government Power (GP), Return on Assets (ROA), Size and age are not significantly associated with the level of Environmental Disclosure.