There are no longer direct ferry services from Rimini to Croatia.

As such, it is better to fly to Venice or Trieste airports if you wish to go to Istria or Kvarner, or to Ancona airport if you want to reach Dalmatia.

If you do find yourself flying to Rimini, take a train to Venice, Trieste or Ancona, and then carry on with your journey to Croatia.

Bologna Forli airport is also in the region; again, make your way to one of the above cities in Italy and then carry on your journey to Croatia.

Flights from the UK to Rimini
Ryanair have flights from London Stansted, Bristol, East Midlands and Liverpool

Flights from the UK to Bologna Forli
Ryanair have flights from London Stansted, Edinburgh and Dublin

Useful Travel Links
Rimini Airport Information from the wonderfully named "Federico Fellini International Airport"
Bologna Forli Airport Information on getting to/from the airport
Trenitalia Train timetables for journeys within Italy