The former Stoke City manager claims that a number of people advised him to steer clear of Selhurst Park, but that Ferguson was very positive when he spoke to him about the vacancy left by Ian Holloway.
"Looking at it, everyone I had spoken to had said it was a difficult one," Pulis told reporters. "Sir Alex Ferguson and Peter Coates, my old chairman, were the only two who said to take it, and they were two good judges. The rest were very negative towards it.
"I hadn't seen Palace play and what they had or didn't have. But I enjoy a challenge. It's in my nature to stand up and try to march people forward and we've done that."
Palace are currently 11th in the Premier League.