A ceremony on Friday afternoon, during which the 18th World Cup was declared open by Horst Koehler, the German president, officially began a month-long festival of football, bringing together 32 teams in 64 matches.
Brazil's Pele and Argentina’s Diego Maradona were among footballing legends from the tournament's past expected to join the ceremony.
The current Cup holders, Brazil, are favourites to lift the trophy again, fielding a team comprising several of the world's top players.
Brazil have won the cup five times and are the only team to have played in all the 17 previous World Cups.
The last time Germany hosted the World Cup, 32 years ago, the then West German team won the tournament in a final, also held in Munich.
The current team, lacking injured star captain Michael Ballack, had been hoping that the venue in Munich would provide a good omen for the month ahead.
Hosts Germany has been hoping
for a good start to the campaign
Immediately after the Germany-Costa Rica opener, a lower-key match in the city of Gelsenkirchen pits Poland against Ecuador, with both sides hoping to break new World Cup ground and advance beyond the first round group stages.
Tight security is in place across Germany, with all police leave cancelled after months of training to deal with the threat of both terrorism and hooliganism.
Border checks have also been reimposed at the frontiers with neighbouring EU countries to prevent suspected troublemakers entering the country.
Another concern for authorities is the threat of racist attacks from domestic far-right groups.
Government officials, eager to present a modern, open face of Germany to the world, have said any such incidents will face swift and firm action by police.
Fans from around the world are
gathering in Germany
Germany is expecting more than a million visitors over the duration of finals, providing a much needed boost to Europe's largest economy, which has seen sluggish growth in recent years.
Overall economists expect tourists will spend about one billion euros ($1.27 billion) in the country during the tournament.
Aljazeera.net/English will have coverage of every match as well as news from on and off the pitch throughout the tournament.