The 72-year-old Lamoriello announced the change Monday, noting that he will remain as president of hockey operations.
He said he has considered stepping down for a while and that he was not forced out by ownership after missing the playoffs the last three seasons.
"Certainly there has been a certain philosophy here that has been successful for a number of years and I think the decision was getting someone who had experiences in different organizations, but also has had the background in winning and knows what it is to win and has experienced winning," Lamoriello said in explaining the move. "That's pretty important in anything you do. There is a difference."
The 52-year-old Shero was let go as the Pittsburgh Penguins general manager last May. The Devils received permission from the Penguins to talk with Shero, but they were not compensated for the hire.
Shero will run the team, and he will be in charge or hiring a new coach, said Lamoriello, noting that Shero will report to him.
Sidney Crosby scored again as Canada beat host Czech Republic, 6-3, at the ice hockey world championship, and the United States bested defending champion Russia, 4-2.
It was the third win in three games for both North American teams and Sweden equaled their record by routing Latvia, 8-1. Last year's runner-up Finland blanked Norway, 5-0, for its second win.
Philadelphia Flyers center Sean Couturier broke a 2-2 tie for Canada 2:20 before the end of the second period. Dallas Stars forward Tyler Seguin and Crosby both scored power-play goals in the third. The Pittsburgh Penguins star has scored a goal in each game at the worlds. Tyler Toffoli of the Kings added an empty net goal with 1:29 left.
Trevor Lewis of the Kings scored one of the goals for the U.S. in its win over Russia. The Americans have outscored their three opponents, 11-4.