Open AccessThis study aims to investigate narrative TBL reporting in the annual reports of the top 50 largest companies listed on the Stock Exchange of Thailand (SET), to establish whether there is any relationship between the extent of TBL reporting and a variety of factors used in previous studies conducted in more developed countries. By using a non-probability sampling method, the top 50 listed companies were sampled based on their 2010 annual reports. Statistical analysis (descriptive, multiple regression, independent samples t-tests, and ANOVA), was employed to analyse the extent of reporting found and the relationship between TBL disclosure based on a measured score and ten characteristics influencing disclosure identified in previous studies.The findings show that there are statistically significant differences between the TBL reporting scores of high and low profile companies. There are also significant differences in reporting based on industry groups. Although the results did not indicate any relationship between TBL disclosure scores and the various factors considered in previous studies, there was a correlation between the age, type of business, and liquidity of companies and their economic information reporting score as well as between the size, risk, and profitability of the company and the environmental information disclosure score.