Air passengers who reach their final destination three or more hours after the scheduled arrival time can claim compensation between €250 and €600 from the airline.
The ruling was announced by the European Court of Justice in Luxembourg, which was confirming a view it took back in 2009.
The size of the award matches that of air passengers who are inconvenienced by cancelled flights.
The ECJ found however that compensation would not apply under what it termed "extraordinary circumstances".
The ruling follows requests for clarification from courts in Germany and Britain on the scope of the compensation law.
The European Court of Justice said today it was reiterating the principle of equal treatment.
It said this requires that passengers whose flights are delayed and those whose flights are cancelled "at the very last minute" must be regarded as being in comparable situations.