Hodgson's affable personality comes across clearly in public appearances and England's players have often spoken about how much they enjoy working under the engaging coach.
But, if they fall out of line, Hodgson's players are never spared a dressing down, according to Lewington, who has developed a close bond with the England manager during their five years together with Fulham and the national side.
"What you see is what you get with Roy, but people will be surprised to hear that he has a nasty side to him too," Lewington said in an interview for Crystal Palace's website.
"You ask some of the members of the Fulham squad. They know about it. It wasn't a forced anger. When he was angry he was genuinely angry and the players knew about it.
"He can be difficult to work for sometimes because he demands that everyone does their best. He has high standards. He is a very articulate, charming man, he does the does the job as he sees it and everyone has to get to that degree of excellence.
"If you don't, he tells you. He is what you see but he has also got that other side you don't see."
Lewington and Hodgson face the biggest challenge of their careers this summer when they take England to Brazil for the World Cup, with one bookmaker offering odds of 66-1 on England to win the tournament.
But that has not diminished Lewington's appetite for the World Cup.
Lewington added: "We have an absolutely fantastic group of players.
"At the moment we are still pinching ourselves. It seems a long way off but in reality it's getting closer and closer. We cannot wait.
"I am sure we will give a good account of ourselves."
Hodgson said earlier this week that World Cup places were still up for grabs, but Lewington conceded the two already had a rough idea of the 23-man squad they would take to Brazil.
One man who appears to have just missed out on the World Cup is Tom Ince.
Crystal Palace signed Ince, son of former England international Paul Ince, on loan from Blackpool on transfer deadline day and he has already made a big impact.
Lewington confirmed that he and Hodgson had considered promoting Ince from the England Under-21 squad, but the midfielder looks like having to wait until after the World Cup to earn his first cap.
"Tom Ince is quality," Lewington added.
"Roy and I have seen him. He is one that we have been looking to pencil in a couple of times.
"I think it's a little bit too late for the World Cup but he is certainly England's future. He is a really good top-quality player."