There currently is one option to travel by night train from Munich to Warsaw, taking between approximately 14 and 15 hours: Namely the EN 406 operated by ÖBB.
The Austrian Federal Railways (ÖBB) operate the Nightjet and Euronight trains (the latter together with other national railway agencies). ÖBB night trains typically feature three types of carriages: seats, couchettes, and sleepers. While seats are only for the bravest, couchettes and sleepers offer a more comfortable journey. Couchettes accommodate up to six people, while sleepers are private compartments for one to three people. They may include a private bathroom or shower, or sometimes just a sink.
For the next 7 dates with connections, the cheapest offer starts at 145 EUR. Check our connection pages below for all availabilities!