Air
Bratislava Airport (BTS) has flights from several European cities, mostly via low-cost carriers like Ryanair and Wizz Air. However, many travelers fly into Vienna Airport (VIE), which is only 60 km from Bratislava and has far more international connections. Regular bus services connect Vienna Airport to Bratislava in about an hour. Kosice Airport in eastern Slovakia handles a few European routes.
Rail
Trains connect Bratislava to Vienna (1 hour), Budapest (2.5 hours), Prague (4 hours), and Warsaw. The train from Bratislava to Kosice takes about five hours and crosses the country through some scenic territory. Bratislava's main station (Hlavna Stanica) is within walking distance of the old town.
Bus
FlixBus and RegioJet operate extensive international routes to Bratislava from Vienna, Prague, Budapest, Krakow, and other cities. Buses are often cheaper and sometimes faster than trains, particularly to Prague. Bratislava's main bus station (Autobusova Stanica) is centrally located.
Car
Slovakia is well connected by motorway to Austria, Czech Republic, Hungary, and Poland. A motorway vignette (electronic toll sticker) is required for using Slovak highways -- buy it online before crossing the border or at petrol stations. Driving from Vienna to Bratislava takes about 45 minutes.