Zurich airport offers the cheapest routes to Bangkok, from ฿14,238; whereas Geneva Geneve-Cointrin airport is typically cheaper if you're flying to Bangkok, from ฿22,231. It's best to make sure you are flexible on dates to find the cheapest possible flight options for your journey.
Here are some of the cheapest flight destinations from Switzerland:
Fly from Zurich to Bangkok from ฿14,238
Fly from Zurich to Phuket City from ฿23,742
Fly from Zurich to Koh Samui from ฿28,074