AirHint found the following cheapest return flights from Mumbai (BOM) to Kathmandu (KTM) in September 2025 (see full year).

Return flights

03 Sep - 20 Sep	Air India
12 Sep - 15 Sep	Nepal Airlines
12 Sep - 14 Sep	Nepal Airlines	direct
11 Sep - 12 Sep	Air India
02 Sep - 12 Sep	Air India
01 Sep - 12 Sep	Air India
06 Sep - 12 Sep	Air India
12 Sep - 19 Sep	Air India
07 Sep - 19 Sep	Air India
10 Sep - 12 Sep	Air India
01 Sep - 23 Oct	Air India
21 Sep - 07 Oct	Nepal Airlines
24 Sep - 13 Oct	Nepal Airlines
18 Sep - 05 Oct	Air India Express
18 Sep - 03 Oct	Air India Express
18 Sep - 02 Oct	Air India Express
24 Sep - 15 Oct	Nepal Airlines
21 Sep - 12 Oct	Nepal Airlines
28 Sep - 06 Oct	Nepal Airlines
13 Sep - 03 Oct	Air India Express

Also check the deals for one-way flights from Mumbai to Kathmandu 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 Mumbai to Kathmandu in September from 142€

Return flights