Best route by rail from Ljubljana to Venice in mid-June?

I have the same question but wondered if driving would be more economical. What are the reputable car companies in Ljubljana?

This is one situation where I would consider bus instead of train. www.drd.si is the Slovenian bus company that runs a daily 815am bus from Ljubljana to Venice Mestre. I think it's about 25Euro per person and it's 3 hours and 15 minutes total. The train is going to be at least 4 and a half hours if you go through Villach. I did not check direct purchase prices but on Rail Europe's generally overinflated price chart it was much more expensive than a 25Euro bus ticket.

You can take a hydrofoil from Pula...find the time tables and details online. The train schedule is not friendly and one way car rentals if available are very expensive.
And Pula is a lovely place to spend a few quiet days before hectic Venice.

Italy isn't too friendly to international railway connections, so they are generally quite poor. That said, if you're up for a more scenic ride, you can take a train from Ljubljana to Villa Opicina, the border station in Italy, get off the train and take a local bus to Trieste (a couple of miles) and then take a train to Venice. Alternatively, like someone else suggested, take the DRD bus to Venice or book a shuttle transfer with GoOpti at www.goopti.com

I have used Goopti to travel from Venice to Ljubljana in June 2013. For your trip Goopti would originate at the train station in Ljubljana and drop off at various locations in Venice. Cost was 30-35 euro and the vans they use are late model, clean and very nice. The vans carry 6-8 passengers. Hope this helps in your planning. Judy

We plan on taking the DRD bus from Venice to Ljubljana in September....they can also do a private transfer. Would rather spend 3-4 hr in transport than 6 or so by train.

Thanks to all for the various suggestions. I checked the Go Opti shuttle and it sounds as if it would work especially with four of us. It's good to hear that others have tried it. I like the idea that we could be dropped off right the Piazzale Roma. If I understand how it works, with four people we would have more control over the timing, even if it cost a bit more. If anyone has used this I'd appreciate their comments. Thanks a bunch.

Last year my boyfriend and I used GoOpti from Verona to Ljubljana. We were the first to be picked up and then we stopped at three airports to pick up other passengers. It was actually quite quick and a great experience. It was around 50euros for both of us. Really cheap!

Thanks for all the great suggestions. After reading reviews of GoOpti it sounds like the bus is better.

We used goopti from Venice to Bled traveling via Ljubljana as we had to drop someone off there. It was June 2013, and I was nervous as I read mixed reviews, but for our party of 7, it seemed better than the option of the train. I was nervous even the night before if it was going to work out ok, and I want people to know it was perfect. A pleasant ride, a great driver, a planned stop for bathrooms 1/2 way into our trip, and dropped off at our hotel, instead of the train station. I'd use them again. We've done lots of train travel in Europe and I'm comfortable with that, but if have to say Goopti was relaxing as we didn't have to think where we were going.