AirHint found the following cheapest return flights from Basel (BSL) to Bangkok (BKK) in September 2025 (see full year).

Return flights

26 Sep - 29 Oct	Pegasus Airlines
15 Sep - 29 Sep	Pegasus Airlines
20 Sep - 06 Oct	Pegasus Airlines
24 Sep - 06 Oct	AJet
17 Sep - 24 Sep	KLM
19 Sep - 02 Oct	KLM
18 Sep - 01 Oct	KLM
23 Sep - 30 Sep	Pegasus Airlines
17 Sep - 04 Oct	Pegasus Airlines
30 Sep - 20 Oct	Pegasus Airlines
24 Sep - 22 Oct	AJet
30 Sep - 12 Oct	Pegasus Airlines
15 Sep - 22 Sep	Pegasus Airlines
19 Sep - 21 Sep	Pegasus Airlines
18 Sep - 18 Oct	AJet
15 Sep - 25 Sep	KLM
24 Sep - 30 Sep	Turkish Airlines
17 Sep - 29 Sep	Lufthansa

Also check the deals for one-way flights from Basel to Bangkok in September.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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Cheapest return flights from Basel to Bangkok in September from 501€

Return flights