Calling Portugal from the United States explained:

• 011 - US exit code; dial first for international calls made from the USA or Canada
• 351 - Country Code for Portugal
• Phone Number - 9 digits
• US to Portugal international dialing format: 011 351 ??? ??? ???

How to dial to Portugal cellular:

• dialing format for calls to a cell phone: 011 351 9?? ??? ???

Starting digits for landlines in main cities/regions:

• Amadora: 21
• Azores: 292, 295, 296
• Braga: 253
• Coimbra: 239
• Madeira (Funchal, Porto Santo): 291
• Lisbon: 21
• Porto: 22

Phone Books:

• Portugal White Pages by PT Comunicacoes
• Paginas Amarelas - official Yellow Pages