Castiglion Fiorentino is easily accessible by air, train and car.
The closest intercontinental
airport is the Fiumicino hub, located near Roma. Train transportation
is available from there to Castiglion Fiorentino with a travel time of
about three hours. The timetable of italian railways is available here.
Coming by car either from North (Firenze) or South (Roma), one can take the A1/E35 highway ("Autostrada del Sole") and exit at Monte S. Savino. Castiglion Fiorentino is roughly 15 km from the exit.
Here is a map of the region.