How long is your layover? I can't speak to your specific situation, but the one time I connected at FRA, I thought there was plenty of time and found I had to dash to the gate. It's a huge, busy, complex airport. Google FRA and print out a map of the airport so you'll have some idea of your route. Maybe someone will respond who can give you better help. Good luck!

We're overnighting in Mainz on a trip home from Europe late this month and will fly out of FRA so could also need some good luck.

Frankfurt is your entry point to Schengen therefore you pass through immigration, though unlike 3rd world countries you don't have to collect and recheck luggage.

If you have booked it as one ticket then you won't have been allowed to book impossible connection times and if things do go wrong it's up to Lufthansa to sort things out.

However as has been pointed out Frankfurt is a large airport with long walk times so don't dawdle.

Look at the airport map: http://www.frankfurt-airport.com/content/frankfurt_airport/en/directions/airport_maps1/terminal_1_2.html

1. Both flights being "terminal 1" does not necessarily improve the situation. Terminal 1 has C,B,AZ wings. B and A are so far apart it might as well be different terminals.

2. Your planes may not get gates on the concourse, but may have to be bused to/from airport -- adding 15-30min to your transfer. You don't know which part of terminal 1 your plane arrives until the plane actually touches down. Similarly, the departure gate for you FLR plane will not get finalized until the last minutes. However, in my experience, they are at least nice enough to keep within each wing. When you arrive in FRA, for example, if the digital display at FRA for your FLR flight says gate 1A-nnn, then they often change the gate assignment at last minutes but at least it would be something like 1A-mmm.
The gate assignment for continuing flight from FRA printed in your boarding pass you get in US is likely to be completely incorrect. Check the departure gate assignment frequently. It is very fluid at FRA.

3. At FRA, you go through a) passport control and b) carry-on security check. Both can be quite time consuming. If you transfer is within 1B to 1B, there is a separate, if difficult to find, passport control + security check just for this purpose that can steer away from having to go thru general passport control. When you get off plane ASK the Lufthansa agent at the arrival gate where is (the current understanding of) your next flight, which might be still off the small connection flight screen, and which passport control you should use. If you connection is really short, they might offer you a faster way.

4. Even though I have gone thru what seemed like mind bogglingly long queue through passport control and carry-on security check, the FRA staffs are very efficient and I have yet missed flights with at least 90min layover time.

5. Checked luggage retrieval is done at FLR. If have nothing to declare, custom process means walking through the door "nothing to declare" -- a 3 second process. Different airport handles non-Schengen originated luggage differently. Some airports dump all the luggage irrespective of the original onto same carousel. Other airports directs non-Schengen originated luggage onto different carousel. This is usually noted on the digital display at the carousel.

Not sure why you won't have boarding pass for your 2nd flight. LH at PHL should issue you the boarding pass. If you don't you can just walk to the gate and they'll issue one there.

dtraveler2006,
After reading J62 and your original post, I realized you might be leaving out a crucial detail in your post.

Is your PHL-FRA-FLR leg booked as one reservation? That is what you really bought was PHL-FLR, but FRA was added by the carrier/booking site, because of the necessary layover?

If you have booked PHL-FRA and FRA-FLR separately, they you may be more in trouble, although both flights being Lufthansa should work to your advantage.

Greg, my travel agent says, "Ticket is issued electronicly and as one ticket all the way thru..." Also, I have three hours between landing at Frankfurt and leaving on the Florence flight. What problems were you referring to?