How much is a ticket from Barcelona to Dusseldorf?

The cheapest price found today is $38.

When is it cheaper to fly?

Cheapest month is September — from $38.

Cheapest today — $38. Below is what booking services offer.

Departure	Airline	Stops	Price
Sep 4	Vueling	direct	$38	View
Sep 15	Vueling	direct	$42	View
Oct 19	Vueling	direct	$43	View
Sep 17	Vueling	direct	$45	View
Sep 3	Eurowings	direct	$45	View
Sep 5	Vueling	direct	$47	View
Sep 7	Vueling	direct	$48	View
Sep 21	Eurowings	direct	$49	View
Sep 10	Eurowings	direct	$49	View
Sep 30	easyJet	1	$52	View

How much is a ticket from Barcelona to Dusseldorf?: The cheapest price found today is $38.
When is it cheaper to fly?: Cheapest month is September — from $38.

Links to booking services are affiliate links. The price stays the same for you.