Booking train from Trieste Centrale to Ljubljana -- how?

I would advise you rather take the bus (Flixbus or other line) which departs also from Trieste Central Station to Ljubljana
It takes 1.30 hour.
I would advise you to download Trainline app where you can see all European train lines. You can also pay with your credit card.

I would love to take this train someday - not because it will be amazingly scenic but because I'm glad it's finally running after all these years! The bus would be a little quicker, but I greatly prefer trains - so much more fun and a smoother ride.

As said above, the train can't sell out so no worry about buying tickets in advance. You might even be able to buy them on the train (unlike Italian trains). I've bought tickets on Slovenian trains before.

I am having the same problem as Sarah. So, is it NOT possible (Trieste to Ljubljana)
to buy an international ticket online? But, I can buy one while in Trieste before my Ljubljana travel date? I have looked into taking a bus from Trieste to Ljubljana and I am hesitant to use "Optic" bus or Flixbus because of the very bad reviews from various ticket holders.

Please let me know when you have time.

Thanks,
Cathy

Right, no change to the earlier info in the thread. You'll have to buy tickets at the station, but they cannot sell out, since the train doesn't take seat reservations.

You can purchase tickets through RailEurope (and pay a processing/delivery fee). Ultimately, I bought ticket in person in Trieste -- easy to do, train was nearly empty (this was end of April, not peak travel season, though).

And because it's a Slovenian train, you probably CAN buy them on the train. (Don't try that with an Italian train!!!) I would still try to buy them at the station if you have time, of course, but if for some reason you are running really late, I'd get on the train without a ticket and buy one from the conductor.