Croatia is a member of the Eurolines system - Europe's largest and best connected scheduled coach operator. It connects over 500 cities in 25 European countries. Coach operators from many countries organize scheduled and ad-hoc lines to Croatia, with or without packages. In summer months there are numerous tourist coach lines from all European countries to Croatian destinations. Check with the travel agencies in you country specializing for travel to Croatia.
Many Croatian coach operators maintain scheduled international coach lines covering all major European cities, as far as London, Paris, Rotterdam and Amsterdam, many cities in Germany, Belgium, Switzerland, Italy, Slovakia, Czech Republic, Slovenia, Hungary, Bosnia and Herzegovina, Serbia, Montenegro and Macedonia.
Not only it is well connected with various bus routes from abroad, Croatia is well connected within the country itself. There are express buses and coaches which cover longer distances and are very comfortable. Most of them are air conditioned too. Bus travel around Croatia is not expensive, there is variety of route choice and the new motorways in parts of the country have reduced journey times too.
Bus service between major cities (intercity lines) is quite frequent, as well as regional services. The most frequent bus terminal in Croatia is Bus Terminal Zagreb (in Croatian "Autobusni kolodvor Zagreb"). On their official pages you can find the timetable of all arrivals to Zagreb and departures from Zagreb. In almost every larger town, there is a bus station (Autobusna Stanica) where tickets are sold and timetables are clearly displayed.
Croatian travel agencies have their own fleets of modern motor coaches and mini buses. They can be hired or transfers can be organised with or without interpreters or guides, assistance and porterage.