This study investigates the corporate environmental disclosure practices of companies on the Stock Exchange of
Thailand in annual reports and websites. Content analysis by word count is used to determine the amount of
disclosures on 50 sampled websites and annual reports. Statistical analysis (descriptive, paired samples T-tests,
and independent samples T-tests), is employed to analyse the differences between environmental disclosures
measured by word count in annual reports and on websites. Initial findings indicated that 96 percent of the
sampled Thai listed companies provided environmental disclosures in their annual reports and 88 percent on
websites. Companies providing the most words of environmental information were in the resources business
group in both media; the smallest word counts were in the services business group on websites, but in the
technology business group in annual reports. Commonly environmental disclosures were found in the corporate
social responsibility section of the websites but in the corporate governance section of the annual reports. The
three most common themes were environmental spending and activity, waste management, and environmental
policy in both annual reports and websites. Statistically significant differences were found between high and low
profile companies as well as government and private companies. However, this study could not find different
amount of environmental disclosures made in annual report and on websites. The study has implications in
enhancing the understanding the differences between disclosures in annual reports and on websites particularly
in developing countries. The usual limitations associated with sampling, and content analysis apply. Disclosure
quality was not considered.