Comparison between the slightly edited R-Rated Theatrical Version (as broadcasted on Austrian TV-station ORF) with the uncensored Unrated Version (represented by the German DreamWorks DVD).

As many other sexual based comedies "Old School" needed to be trimmed to receive an R-Rating. 6 cuts running 79 seconds altogether are missing in said R-Rated version.

Running time of the Theatrical Version without end credits: 82:23 min (PAL).
Running time of the Unrated Version without end credits: 83:42 min (PAL).

Time specifications refer to the German DVD.

All dialogue from the German report had to be re-translated into English and therefore may differ from the original dialogue. - the translator

3.53
Extended scene of Heidi watching the porn.
8 Sec

4.16
The second close-up of the TV set where the porn is playing is rudimenatry seen in the R-Rated version (1 sec). In the Unrated version the shot is remarkably longer.
3 Sec

4.33
The two naked girls leave the bathroom in different shots.
R-Rated: Mitch takes of the jacket while in the background the two girls are coming out of the bathroom. Then there's a short shot of Heidi.

Unrated: Here the two leave the bathroom in a close-up.

1 Sec

20.42
Drunk Frank runs through a street naked and invites others to streak with him.
18 Sec

42.19
Different shot of the blowjob instructor telling the women that the sailor never called him. In the Unrated version his tale goes on a little longer.
R-Rated: Close-up of the instructor. He says: "...who never ever called me..." (2 Sec)

Unrated: Long shot, he says: "...and who never called me back but who left me with a little surprise called herpes which I gave on to my dog." (8 Sec)

6 Sec difference

42.56
The instruction lessons have been trimmed heavily in the R-Rated version. The instructor shows much longer how to do it right. The women imitate him with their "instruction tools".
Instructor: "That's good, Marissa. Careful with those teeth. We don't wanna bite. Alright, now work it, those carrots don't ejaculate by themselves, ladies. From nothing nothing comes. [He begins to judge his "students.] Very good. Really good. Good. Good. Good. Not. so good. What are you doing? You're sucking like Romulus on the tits of Mother Wolf...if you know your Greek mythology. Excuse me, we're here for blowjobs, not for sucking off the tits of mythological creatures.
A woman laughs out.
Instructor: "Oh, you think this is funny? You won't laugh so hard anymore when all of a sudden someone busts a load in your face. Cause it burns. And that's why I only have half of my vision on my right eye. Thank you - and continue, please."
43 Sec