| Contracting Party | Treaty | Signature | Instrument | In Force | Details |
| Portugal | Berne Convention | | Accession: March 29, 1911 | March 29, 1911 | Details |
| Portugal | Brussels Convention | | Accession: December 11, 1995 | March 11, 1996 | |
| Portugal | Budapest Treaty | | Accession: July 16, 1997 | October 16, 1997 | |
| Portugal | Lisbon Agreement | October 31, 1958 | Ratification: June 9, 1966 | September 25, 1966 | Details |
| Portugal | Locarno Agreement | October 8, 1968 | | | |
| Portugal | Madrid Agreement (Indications of Source) | April 14, 1891 | Ratification: October 31, 1893 | October 31, 1893 | Details |
| Portugal | Madrid Agreement (Marks) | April 14, 1891 | Ratification: October 31, 1893 | October 31, 1893 | Details |
| Portugal | Madrid Protocol | June 28, 1989 | Ratification: December 20, 1996 | March 20, 1997 | |
| Portugal | Nairobi Treaty | October 24, 1981 | | | |
| Portugal | Nice Agreement | June 15, 1957 | Ratification: April 28, 1959 | April 8, 1961 | Details |
| Portugal | Paris Convention | March 20, 1883 | Ratification: June 6, 1884 | July 7, 1884 | Details |
| Portugal | Patent Cooperation Treaty | | Accession: August 24, 1992 | November 24, 1992 | |
| Portugal | Patent Law Treaty | June 2, 2000 | | | |
| Portugal | Rome Convention | | Accession: April 17, 2002 | July 17, 2002 | |
| Portugal | Singapore Treaty | March 28, 2006 | | | |
| Portugal | Strasbourg Agreement | | Accession: April 28, 1978 | May 1, 1979 | |
| Portugal | Trademark Law Treaty | October 28, 1994 | | | |
| Portugal | UPOV Convention | | Accession: September 14, 1995 | October 14, 1995 | Details |
| Portugal | Vienna Agreement | June 12, 1973 | | | |
| Portugal | WIPO Convention | July 14, 1967 | Ratification: January 27, 1975 | April 27, 1975 | Details |
| Portugal | WIPO Copyright Treaty | December 31, 1997 | Ratification: December 14, 2009 | March 14, 2010 | |
| Portugal | WIPO Performances and Phonograms Treaty | December 31, 1997 | Ratification: December 14, 2009 | March 14, 2010 | |