The 38-year-old actor, who took over the role of the Doctor in the popular BBC series in 2005, indicated he had a difficult time keeping his feelings in check his last day of work on the show, the BBC reported Friday.
"There's lots of scenes in the final episode that are very sad, and were very sad to play," Tennant said.
"On the actual final day I was a bit of a puddle, but kept a mildly stiff upper lip."
Tennant will appear in an episode titled "The Waters of Waters" on BBC One Nov. 15 before his character once again battles with his rival, The Master, in two episodes during the Christmas holiday.
Tennant told the BBC he was excited yet concerned that actor Matt Smith, 27, would serve as the 11th incarnation of the show's lead Time Lord.
"I'm thrilled that it's carrying on," he said, "and know that everyone who's there is a great choice, but of course you feel a bit proprietorial."