3.1 million viewers tuned in for part one of Armstrong's interview Thursday night.
The number was still less than Oprah's first interview with Whitney Houston's daughter Bobbi Kristina which had 3.5 million viewers in March.
Back-to-back telecasts of the interview earned 4.3 million views.
The interview did gain more than Oprah's interview with Rihanna in August which had 2.4 million viewers.
Armstrong's interview on