According to Bang Showbiz, the actor is surprised when people describe his character as sexy.
"Sexy?" he said. "Do you think he's sexy? The Doctor's a bit bumbly, isn't he? He doesn't really know what to do with women."
Smith also claimed that people started treating him differently after he joined the cast of Doctor Who.
"There's no doubt that when you're on screen every week, people look at you differently and you just have to adapt to that," he said. "The way you'd adapt if, say, your hair turned white overnight. A lot depends on the context of your life - maybe if you've grown up with a family who were famous or something, you'd have a different perspective, but for me it's a totally new thing and I try to adapt as intelligently as I can."
The finale of Doctor Who airs on Saturday at 6.05pm on BBC One.