It is currently possible to buy a cheap return ticket on Zagreb - Brussels - Zagreb route!
The well-known Belgian airline, Brussels Airlines, has announced its return to Zagreb in the summer of 2021. Considering that from the beginning of summer flight schedule (end of March) Brussels will fly to Zagreb again, it is currently possible to buy cheap return tickets between the two mentioned cities.
22.04. - 25.04. from 89 eur,
21.04. - 25.04. from 98 eur,
07.05. - 09.05. from 98 eur,
03.06. - 06.06. from 82 eur,
16.06. - 23.06. from 81 eur.
You can find cheap tickets by entering the dates on Skyscanner (LINK), but those can also be found on the official website of Brussels Airlines. Under normal circumstances, Croatia Airlines also operates on this route twice a day, while Brussels Airlines has up to 5 flights a week during the peak summer season.
Cheap flights to Brussels can be found on low-cost airlines from coastal Croatian airports, with flights departing mostly from Pula Airport (Ryanair).