The Seleccao have been drawn into a daunting group alongside Germany, the USA and Ghana, and kick off their campaign against Joachim Low's side June 16.
Coach Paulo Bento has named his provisional roster, which will be whittled down to a final squad of 23 on May 19. Ronaldo is the headline name and features alongside Madrid teammates Pepe and Fabio Coentrao.
Meanwhile, Porto's Ricardo Quaresma has been included after returning to his old club earlier this season.
Goalkeepers: Anthony Lopes (Lyon), Beto (Sevilla), Eduardo (Braga), Rui Patricio (Sporting Lisbon)
Defenders: Andre Almeida (Benfica), Antunes (Malaga), Bruno Alves (Fenerbahce), Fabio Coentrao (Real Madrid), Joao Pereira (Valencia), Neto (Zenit St Petersburg), Pepe (Real Madrid), Ricardo Costa (Valencia), Rolando (Inter)
Midfielders: Andre Gomes (Benfica), Joao Mario (Vitoria), Joao Moutinho (Monaco), Miguel Veloso (Dynamo Kiev), Raul Meireles (Fenerbahce), Ruben Amorim (Benfica), William Carvalho (Sporting Lisbon)
Attackers: Cristiano Ronaldo (Real Madrid), Eder (Braga), Helder Postiga (Lazio), Hugo Almeida (Besiktas), Ivan Cavaleiro (Benfica), Nani (Manchester United), Rafa (Braga), Quaresma (Porto), Varela (Porto), Vieirinha (Wolfsburg)