While the Americans fell flat, the Czechs got an early goal from tall striker Jan Koller and two more from Tomas Rosicky in Gelsenkirchen.
It wasn't all good news for the Czechs. Koller was taken off the field on a stretcher in the 43rd minute. He returned only last month from knee surgery, and after the game Czech Republic coach Karel Bruckner said: "Unfortunately his injury is quite serious."
Koller headed a cross past U.S. goalkeeper Kasey Keller in the fifth minute for his 43rd goal in 69 international appearances, a Czech record.
U.S. captain Claudio Reyna came closest to scoring for the Americans, hitting the post in the 29th minute.
"You can't be hesitant," he said. "You have to be aggressive from the first minute. There's no excuse."
Four years ago, the United States reached the quarterfinals after upsetting Portugal in its opening match. But with Monday's loss, the team is 0-8 in Europe in World Cup play.
They even got a pregame pep talk from President Bush, who called from Camp David before the game and wished them well. But they didn't perform up to expectations in front of millions of fans back home and about 5,000 who made the trek to Germany.
"I'm very disappointed in our start," coach Bruce Arena said. "They punished us for every mistake we made."
Earlier in the day, Australia's sensational late comeback, with three goals from the 84th minute until the end, beat Japan 3-1. Italy beat Ghana 2-0 in the late game.
For the Czechs, Rosicky put home a soaring 25-yard shot in the 36th minute, and then added another in the 76th, getting past the American defense off a through pass from Pavel Nedved and beating Keller on a breakaway.
The U.S. team next plays Italy on Saturday.
"With all due respect, that's probably the best team in the group," Reyna said of the Czechs, ranked second in the world by FIFA. "Italy's another tough team and it'll be another tough game, but we have to bounce back and put this game behind us and learn from it real quick."
In Hanover, Andrea Pirlo scored Italy's first goal in the 39th minute with a 22-yard shot through a crowded penalty area into the bottom right corner.
Substitute Vincenzo Iaquinta added the second in the 83rd, taking advantage of a poor backpass from Samuel Kuffour to his goalkeeper.
Ghana had a few scoring chances and showed itself worthy of playing in its first World Cup.
In Kaiserslautern, Tim Cahill scored Australia's first World Cup goal in the 84th after Japan goalkeeper Yoshikatsu Kawaguchi failed to punch clear a throw-in. He added another in the 89th, and John Aloisi scored a third in injury time to seal Australia's first World Cup win in the team's second appearance.
"To do what we did today shows Australian spirit and it's good to be up there with the rugby and cricket players," Cahill said.
Shunsuke Nakamura had given Japan the lead in the 26th minute with a cross that beat Australia goalkeeper Mark Schwarzer.
Schwarzer failed to grab the ball when he crashed into a group of players. Japan forward Naohiro Takahara made contact with Schwarzer as the two jumped, but there was no foul and Schwarzer walked off at halftime shaking his head.
"I complained to the referee afterwards," Schwarzer said. "He said to me that he was sorry, that he made a mistake."
Brazil and Croatia, the other teams in Group F, play Tuesday in Berlin.