Roma to Paris by train - Can I stop in Pisa?

Sure, you have plenty of time to get that done... perhaps the best thing to do is spend the day in Pisa, take a train to Milan, and take the night train to Paris from there. The night train departs Milan at 23:38 and arrives in Paris at 08:19.

You can check out all the possible train options on the Deutsche Bahn website, as it has one of the best schedule planners.

Steven: Would your advice ("sure you have have plenty of time to do that") be the same if you had addressed the part of the question the OP asked where he proposes to go from Pisa to Switzerland "for a day", before going to Paris?

It looks like you assumed Jesus is proposing to go directly from Pisa to Paris, but he's not (from OP: "...if I can stop in Pisa, see the Tower of Pisa and the same day depart to a Switzerland city (I accept suggestions) to spend one day and then continue to Paris.")

Hi Kent,

Thank you for pointing out the error in my advice, although I think you could have been more tactful. I appreciate you having answered Jesus' question as well rather than just posting a response indicating my errors.

Steven: I apologize if I was not sufficiently tactful. I would have let it go but, because English is a second language for Jesus (he made a point of this in his OP), I was concerned that he might interpret your answer as having answering the question he asked.

Jesus,

Yes, you could take an early morning train to Pisa, spend 2-3 hours there, and take a series of trains to any number of points in Switzerland, all in the same day. For example, you could do this and be at Interlaken Ost before 22:00.

To see this for yourself, go to the German Rail site which has detailed timetables for most of Europe. Click on the drop-down flag menu and choose "espanol". On the left-hand side of the new page click on "otras optiones." Enter Roma as your departure point, the town of your choice in Switzerland for your arrival point, and Pisa in the "viaje de ida" field. Choose how many hours you wish to stop in Pisa. After you search and get summary timetables, click on the arrow to the left of each departure time to see the connecting points.

I haven't been to Switzerland so I don't have a recommendation on a place to spend the day before going on to Paris.

Many thanks for all your answers. I´m gonna start searching for trains in the sites you suggested me. I think I´m gonna visit interlaken since is the only city which I have recieved recommendations, mainly because is summer time in europe and interlaken could be one of the few citys with snow in these season (i assume that). Thanks again for the quickly answers. Best wishes!!