AirHint found the following cheapest return flights from San Jose (SJO) to Buenos Aires (AEP) in September 2025 (see full year).

Return flights

25 Sep - 28 Sep	GOL Linhas Aéreas
26 Sep - 06 Oct	LATAM Airlines Group
25 Sep - 09 Oct	LATAM Airlines Group
23 Sep - 16 Oct	LATAM Airlines Group
18 Sep - 27 Sep	GOL Linhas Aéreas
26 Sep - 07 Oct	LATAM Airlines Group
15 Sep - 30 Sep	Avianca
14 Sep - 20 Sep	Avianca
14 Sep - 21 Sep	Copa
30 Sep - 30 Oct	Avianca
18 Sep - 25 Sep	Aeromexico
23 Sep - 30 Sep	GOL Linhas Aéreas
25 Sep - 29 Sep	Avianca
15 Sep - 29 Sep	Avianca
18 Sep - 22 Sep	GOL Linhas Aéreas
23 Sep - 12 Oct	Avianca
18 Sep - 05 Oct	Avianca
19 Sep - 01 Oct	Avianca
26 Sep - 04 Oct	Avianca

Also check the deals for one-way flights from San Jose to Buenos Aires 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 San Jose to Buenos Aires in September from 420€

Return flights