There is a regular train service between Frankfurt/Main airport and Mainz.
The second airport, Frankfurt-Hahn is served by a shuttle bus to and from Mainz. The trip takes about 70 minutes.
A current train timetable to and from the Mainz central station (‘Mainz Hauptbahnhof’) can be found at the "Deutsche Bahn" (German Railways).
The University Hospitals are served by the following bus lines from Mainz central station ('Mainz Hauptbahnhof'):
At the motorway intersection Mainz-Süd (A60/A63), proceed towards the city centre ("Centrum") following the signs ‘Universitätskliniken’.
Get directions using Google's free map program:
Department of Urology