From the ThornTree Forum: You need an international license to legally rent - I'm sure a bit of money can get you around this, but you are opening yourself up to larger problems if there is some sort of a problem. Police will not take kindly to your abrogation of the laws (again, this is something you can throw money at to make go away) and the health insurance may refuse to cover costs in case you have an accident without the appropriate driving license.
Some ASEAN countries recognize each other's licenses. If you don't therefore have a Thai, Singaporean, Malaysian or Laotian drivers license you should have an International Drivers License. Laos though may insist that you have an International Driving License - they stopped me with a Thai driving license and insisted that I need an International Licence. In the end, when I refused to pay, they waved me of.
