Trouble finding train route from Vienna to Athens

The German Rail website shows one connection with 5 changes - Budapest, Bucharest, Ruse Bulgaria, Sofia, and Thessaloniki - starting from Vienna at 15:42 daily. The trip takes over 60 hrs including a 16 hour overnight stopover in Sofia.

Other issues affecting your journey is that Greece traditionally has not been a "train country". Other than the main line between Thessoloniki and Athens, a spur line up to the Meteora, and limited service to the Peloponnese, the country is largely un-served by rail.

Part of the reason is up to the end of the Cold War, travel across the Balkans, Bulgaria, Albania and the other countries was not easy, and is still a bit cumbersome, but getting better. The other issue is distance, over a 1000 miles.

If you were to commit to this, I would plan on a couple overnights (Budapest, Sofia, maybe get over to Bucharest.

Read this webpage: http://www.seat61.com/Greece.htm
It is assuming you are starting from London, but one of the routes shown is via Austria.

There is one important paragraph:

IMPORTANT: TRAIN CANCELLED SEPT 2016 TO SPRING 2017: This Belgrade - Thessaloniki train is cancelled completely from early September 2016 until spring/summer 2017 due to major track reconstruction in Serbia south of Nis. It should resume in spring or early summer 2017. There is no bus replacement - during this period you may prefer to go London to Sofia as shown here, then use the Sofia-Thessaloniki train which is unaffected.

Build your own route.

Rome2rio.com shows a bus from Bratislava to Athens in 18.5 hours with stops in Rajka, Budapest, Horgos, Tavanovce, Evzonoi, Thessaloniki, Katerini, Larissa, Larnia. It says there's one bus per week. Bratislava is a day trip from Vienna. You can go by train from Vienna or Bratislava to Budapest (a great place to spend an overnight or a week). From there, look for a route to Athens. If you want to stop in Belgrade, it's a short flight, a long bus ride or a longer train ride. From there, the best option seems to be a flight to Athens. There's one daily bus from Belgrade to Tavanovce (on the Serbian-Greek border), then one bus a week from there to Athens. Google Tavanovce and the first umpteen hits are about the refugees/migrants. I'd fly over it, either to Athens or Thessaloniki. From there train, bus or plane to Athens.

I traveled through the Balkans in 2015, but I started with Munich-Ljubljana and did not go to Greece. Both buses and trains move slowly through Romania and Bulgaria. I figured I covered about 30 mph (50 kph), and that was using the most efficient means possible (buses sometimes being faster, as already noted). Unfortunately, Sofia is not (to me) the most interesting place in Bulgaria and Bucharest (to me) is not the most interesting place in Romania. Those two countries have many points of interest if you don't have to bomb through them. I certainly wouldn't want to make the trip by bus or train if I didn't have time to make some stops.

The problem is not only do trains or buses move slowly, but if there's a once-weekly bus and it's cancelled, you could be stuck for a few days.

Unless you have unlimited time (and money) to allow for unplanned layovers, fly from Vienna to Athens and use that travel time to explore Greece. You could probably find a cheap flight that would be much less expensive than the trains/buses/hotels that a ground trip would require.

Or train to Budapest and stop there for a few days, and then fly to Athens. Or something similar.

Thanks everyone for your thoughtful responses! Geez things sure do take a different turn in terms of transportation once you get south of Slovenia, huh? So the no-brainer solution, given that I don't have endless time AND money, was to do Budapest, then Vienna, then fly from Prague to Athens for the cost equivalent to beans. BEANS, I TELL YOU!!

Thanks again :-)

Can I trade my dollars for some of those BEANS?

Budapest, Prague, Vienna - all great choices. Just leave enough time in each city to see more than just the highlights. Athens . . . dunno, but I will soon. In less than 5 weeks. I'm taking the RS tour there and, in reading up on it, there's a lot more to Greece than Athens . . . . leave some time for the Peloponnese.

Last year we were in a bind getting from Lake Bled (the end of the RS Eastern Europe tour) to Venice. Our tour bus driver recommended go-opti.com and we connected with an 8 passenger van going there. We were picked up at a convenient location, picked up a few other Americans/Brits and had a very convenient, safe, insured, and fairly inexpensive ride from point A to point B. Our bus driver said that was the way all the bus drivers got back to their original location. We felt safe, and saved hours of transportation time with co-opti.com. Highly recommend at least trying to see if it is a possibility.