My wife and I are 71 and 81, in reasonable health. We're trying to plan a two-week July or August trip beginning in Krakow and continuing north to Vilnius, Riga and Tallinn, with perhaps one or two side trips. Our biggest concern is whether to do this by rental car, trains or bus. Hoping an experienced traveler to these countries can advise with method, or combination, is "best" in terms of convenience and price.
1) Rental cars have been my preference in the past. But we've been shocked to see Sixt and Enterprise adding about $1,700 to $2,000 for 'taxes & fees" on top of the add-on charges for travel to another country and dropping the care there.
2) Trains would probably be our second choice. But I can foresee confusion and hassles due to scheduling, switching trains and maybe language.
3) Riding by bus would normally be our least favorite way to go, but I was pleasantly surprised to see that busses are not to be dismissed in that corner of the world?
Our main goals are to see the old towns and some cultural attractions of the Baltic capitals. And I understand that driving and parking within the medieval streets would not be advisable. We would very much appreciate any advice from fellow travelers who have "been there and done that".

Would you consider taking a couple of ferries?
That would require a side trip to the Stockholm area.

I could be mistaken, but I would not expect trouble with language on the trains -- particularly given the ubiquity of translation aps on smart phones.

Have you consulted seat61.com about the train options?

Recent thread had me looking at trains in the Baltic again and they keep getting better. rome2rio and seat61.com are a good place to start

Thanks for your reply, but we would not want to use ferries.

Hi there,
I haven’t traveled from Krakow to the Baltic countries, but I did visit all three Baltic capitals and several other towns in the region using public transportation.
To get from Vilnius to Riga, I took the bus — it works very well. Lux Express, FlixBus, and other companies run this route, so it’s best to use a price comparison site to find the schedule that suits you.
We went from Riga to Tallinn by train, stopping along the way in Cesis. Cesis is a small but very pleasant town. We really liked staying at the elegant Hotel Cesis — the name fits it perfectly. There are also a few good restaurants such as Vanadzins Ziemelu Restorans. From Cesis, you can easily visit the beautiful Gauja Valley nearby — just take the train to Sigulda, then a bus.
For the trip from Riga to Tallinn, there’s a train transfer in Valga, but it’s very easy. Both trains meet on the same platform, and their schedules are synchronized.
Enjoy your trip to the Baltic countries!

It pains me to say it but have you looked at flying? I think Wizz Air fly from Krakow to Vilnius.
The problem with land travel is you have to go around the Russian enclave which make for long 9-12 hours journeys by train or road.

Warszawa - Vilnius is a 7 1/2 hrs journey, either by direct bus or by train witth a train change at the border.
Take the train if you want to stop over at Kaunas.
Kaunas - Klaipeda is easier and faster by bus..
The choice will depend on the places you pan to visit in the Baltic States.
There are tons of trains between Krakow and Warszawa: 2 3/4 hrs journey

Most flights between Krakow and Vilnius are either very early in the morning or very late in he evening.
Air Baltic has a more convenient early afternoon flight, but on Saturdays only.

Thanks hetismij2 .... Sorry, but I don't understand what you mean by going "around the Russian enclave". Please explain, thanks.

There is a Russian-owned port on the Baltic - the enclave that hetismij2 mentions. It is to all intents and purposes legal Russian territory. I don't think you can go through it (I assume that it is somewhat sensitive with navy and whatnot), so you would have to circumnavigate it.

Lavandula

We traveled by bus going from one Baltic capital to another and by train between Vilnius and Kaunas. We wouldhave preferred the train, but we chose the bus between Tallinn and Riga because it did not involve a transfer at the border, and between Riga and Vilnius we could not find out where to buy the tickets. Besides there was only one train and it traveled at an inconvenient time.
Here's my trip report:

Trip report: Tallinn, Riga, Vilnius/Kaunas, June 2025

https://en.wikipedia.org/wiki/Kaliningrad
https://en.wikipedia.org/wiki/Kaliningrad_Oblast

Kaliningrad is Russia. Borders Gdańsk Poland. Your planned travel have no bearing on this area. Enjoy