The determinants of capital structure of 81 listed companies from 6 industries on the Stock Exchange of Thailand from 2004 to 2008 are investigated. After controlling for industry, profitability, size, and tangibility affect leverage significantly. Firms with low profitability, large size, and low tangibility have high leverage. However, growth and volatility do not determine leverage. Furthermore, firms in retail business sector of service industry acquire more funds from short-term debt in order to align with their short-term assets from daily operations.