The protesters demanded a reduction in the price of diesel as well as the resignation of the energy minister.
Several trucks converged on the Energy Ministry in Chatuchak district, blocking the road outside and causing traffic jams during the morning rush hour.
Leading the rally was Land Transportation Association of Thailand chairman Aphichart Phrairungrueng. He also demanded a cut in excise tax on staple diesel, removal of biodiesel from diesel fuel, and the resignation of Energy Minister Supattanapong Punmeechaow.
A ministry statement issued in response to the protest called for understanding from owners of transport businesses over the price crisis, explaining that outside factors influencing energy prices across the globe had resulted in rises in the price of oil, gas and diesel in Thailand.
The ministry said it had taken steps to make pricing conditions easier to enforce, including cutting the three grades of diesel previously available down to a single grade, B5.
The statement said that Thailand was facing problems stemming from higher prices of other fuels, which would soon bring increases in the price of cooking gas and fuel oil needed to generate electricity.