Joachim Loew's men are one of the pre-tournament favourites in Poland and Ukraine, but face a stern test first up in Group B.
With a clash against the Netherlands to follow before a meeting with Denmark, a strong start is a must for Germany in what has been labelled the 'Group of Death'.
The return to fitness of Bastian Schweinsteiger is a boost for Loew's team ahead of the opener, with the Bayern Munich midfielder returning from a calf injury.
Portugal are expected to be heavily reliant on Real Madrid star Cristiano Ronaldo if they are to be successful in a tough group.
The attacker was their top-scorer in qualifying and will have support from the likes of Manchester United's Nani and Real Zaragoza forward Helder Postiga in the attacking third.
Germany captain Philipp Lahm is likely to start at left-back while Jerome Boateng could start on the right, with the pair crucial if Loew's side are to keep Ronaldo and Nani quiet.
The problems for Portugal during qualifying were in defence, conceding 12 goals in eight matches in a group they were expected to top but came second in.
Real Madrid duo Pepe and Fabio Coentrao will lead the back four, with Sporting Lisbon goalkeeper Rui Patricio the first-choice ahead of Eduardo.
Without former Chelsea defenders Jose Bosingwa and Ricardo Carvalho, who both fell out with coach Paulo Bento, Portugal's back four could be exposed by Germany.
Lazio striker Miroslav Klose is again likely to be preferred ahead of Mario Gomez up front despite the Bayern Munich goalscorer's exploits this season.
Behind the lone striker are a dangerous attacking trio, with the likes of Mesut Oezil, Thomas Mueller, Toni Kroos and Lukas Podolski competing for a starting place.
With one of the world's best goalkeepers in Manuel Neuer in goal, Germany deserve their tag as one of the pre-tournament favourites.
They get the opportunity to show what they are capable of in their opening outing against a dangerous Portugal outfit.
soccerway.com