As described in an interview with applicant Tammy Lee, during the first season of The Apprentice (2004), the ending clip each week showing the fired applicant exiting the Trump Tower and entering a cab had actually been filmed during one of the first few days of production before the contest started to cut down on the cost of having to set up for such a shoot each week. Every contestant had this clip filmed regardless of whether they were actually fired or not. From the second season onward, the fired contestants were actually filmed leaving the building after they were fired.
One of only two TV shows to have been hosted by a future U.S. President, the other is Death Valley Days (1952), which was hosted by Ronald Reagan.
The boardroom is on the same floor as the suite the contestants are staying in. So the contestants don't take an elevator up as Donald tells them to.
The contestants had to keep their cell phones on speaker to make sure they weren't cheating by using connections made prior to the show or by making private phone calls.
It typically took 7-1/2 hours to film each Boardroom session. Among other things that end up on the "editing room floor" are expletive-laced interactions and heated exchanges that make the ones that are actually aired seem tame by comparison.