Train from Prague to Vienna

Railjet, joint venture between the Czech National Railway and Austrian National Railway.
Tickets at www.cd.cz or oebb.at

Try this page also for more info:

https://www.seat61.com/trains-and-routes/prague-to-vienna-by-train.htm

We did this trip in the opposite direction in May 2017 and advise making a reservation. From Vienna the train was not full, but it became packed as we went along.