The 6-8, 275-pound Brand and the 6-9, 240-pound Wallace will complement 6-11 Jermaine O'Neal of the Indiana Pacers, 6-11 Raef LaFrentz of the Dallas Mavericks and 6-9 Antonio Davis of the Indiana Pacers on the USA front line.
"The committee did a great job addressing size and versatility by adding two players in Elton Brand and Ben Wallace, who have a lot of width and who will rebound the basketball," said USA World Championship Team coach Don Nelson of the Dallas Mavericks.
The USA Committee on Wednesday also named Kansas senior forward Nick Collison as a second alternate to the team.
The first overall pick in the 1999 draft, Brand was acquired the Los Angeles Clippers last June and averaged 18.2 points, 11.6 rebounds and 2.4 blocks in 2001-02. He ranked first in the NBA in offensive rebounds (5.0) and second in field goal percentage (52.7).
"It's truly an honor to represent your country in international competition," Brand said. "I'm looking forward to facing some of the best players in the world and defending our homecourt in Indianapolis later this summer."
Brand, 23, was voted as the co-Rookie of the Year after averaging 20.1 points and 10.0 rebounds for the Chicago Bulls in 1999-00.
"Elton has quietly become one of the better power forwards in the league, and has emerged as a leader at a young age," Nelson said.
Wallace earned NBA Defensive Player of the Year honors this past season, leading the league with 13.0 rebounds and 3.48 blocks per game to join Hall of Famers Kareem Abdul-Jabbar and Bill Walton and 12-time All-Star Hakeem Olajuwon as the only players to lead the league in rebounds and blocks in the same season.
"Ben just adds so much versatility with his energy, rebounding and shot blocking," Karl said. "With so many scorers on this team, it's nice to add a component that doesn't demand the basketball, but who can create his own offense with effort. Ideally, his energy is contagious, and our whole team can play with that intensity."
Wallace, 27, helped the Pistons win their first Central Division title since 1989-90 as they won 50 games, 18 more than the previous season.
"The fact that I have been picked to play with so many great players shows me the hard work I put into my game this season is paying off," Wallace said.
A six-year veteran who went undrafted, Wallace played three seasons with Washington before he was dealt to Orlando in August 1999. Wallace and guard Chucky Atkins were the players sent by Orlando to Detroit in the sign-and-trade for Grant Hill in August 2000.
The first seven players of the USA World Championship squad -- guards Jason Kidd of the New Jersey Nets, Reggie Miller of the Pacers, Ray Allen of the Milwaukee Bucks and Michael Finley of Dallas, forwards Shawn Marion of the Phoenix Suns, O'Neal and Davis -- were named last November.
On March 12, forward Paul Pierce of the Boston Celtics, guard Andre Miller of the Cleveland Cavaliers and LaFrentz were added to the USA team, and Duke guard Jay Williams was announced as an alternate.
The World Championships will be held in Indiana from Aug. 29-Sept. 8.