AirHint found the following cheapest return flights from Phnom-penh (PNH) to Vientiane (VTE) in September 2025 (see full year).

Return flights

03 Sep - 07 Sep	Thai AirAsia
03 Sep - 05 Sep	Thai AirAsia
03 Sep - 08 Sep	Thai AirAsia
01 Sep - 07 Sep	Thai AirAsia
01 Sep - 05 Sep	Thai AirAsia
01 Sep - 08 Sep	Thai AirAsia
05 Sep - 07 Sep	Thai AirAsia
05 Sep - 08 Sep	Thai AirAsia
01 Sep - 03 Sep	Thai AirAsia
29 Sep - 05 Oct	Thai AirAsia
28 Sep - 03 Oct	Cambodia Airways
16 Sep - 23 Sep	Cambodia Airways
30 Sep - 07 Oct	Cambodia Airways

Also check the deals for one-way flights from Phnom-penh to Vientiane 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.

Book a cheap hotel in Vientiane

Cheap car rent in Vientiane

Cheapest return flights from Phnom-penh to Vientiane in September from 248€

Return flights