If you picked up a visa in Laos before coming back to Thailand, then yes. I'm assuming here you're from a country that makes you eligible for the 30 day visa exemption
Martin Buckhan tourists arriving in Thailand are supposed to have proof of an outgoing flight and the equivalent of
*****
baht CASH. Thing is, they don’t ask for these...until they do! Even if you arrive with a valid tourist visa, the proof of an outgoing flight, and the cash, the immigration officer has the right to refuse you entry to Thailand for whatever reason they see fit. That’s right...even if you have a fresh and valid visa.