Three new cicadas are described from Thailand and Cambodia: Megapomponia atrotunicata Lee and Sanborn, sp. nov., Megapomponia sitesi Sanborn and Lee, sp. nov., and Megapomponia costa ova Lee and Sanborn, sp. nov. Megapomponia decent and Megapomponia rajah are transferred to the genus Pomponia: Pomponia decent (Walker) and Pomponia rajah Moulton. A key to the species of the genus Megapomponia is provided. (C) Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society, 2009 Published by Elsevier By. All rights reserved.