| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| AUSTRIA | Accession | 01/10/1951 | |
| BELGIUM | Signature | 16/09/1950 | |
| BELGIUM | Ratification | 23/04/1954 | |
| BOSNIA AND HERZEGOVINA | Succession | 01/09/1993 | 06/03/1992 |
| BULGARIA | Accession | 08/05/1962 | |
| CZECH REPUBLIC | Succession | 02/06/1993 | 01/01/1993 |
| CZECHOSLOVAKIA | Accession | 06/03/1973 | |
| DENMARK | Accession | 08/06/1966 | |
| FINLAND | Accession | 09/09/1965 | |
| FRANCE | Signature | 16/09/1950 | |
| GERMANY FEDERAL REPUBLIC | Accession | 13/11/1957 | |
| GREECE | Accession | 01/07/1952 | |
| HUNGARY | Accession | 05/12/1962 | |
| IRELAND, REPUBLIC OF | Accession | 20/05/1968 | |
| ITALY | Accession | 27/03/1957 | |
| LUXEMBOURG | Signature | 16/09/1950 | |
| MONTENEGRO | Succession | 23/10/2006 | 03/06/2006 |
| NETHERLANDS THE | Signature | 16/09/1950 | |
| NETHERLANDS THE | Declaration | 04/12/1952 | |
| NORWAY | Accession | 15/12/1952 | |
| POLAND | Accession | 26/09/1960 | |
| PORTUGAL | Accession | 01/04/1954 | |
| ROMANIA | Accession | 07/04/1965 | |
| SLOVAK REPUBLIC | Succession | 28/05/1993 | 01/01/1993 |
| SLOVENIA | Succession | 01/07/1992 | 25/06/1991 |
| SPAIN | Accession | 25/03/1960 | |
| SWEDEN | Accession | 31/03/1952 | |
| TURKEY | Accession | 10/06/1954 | |
| UNITED KINGDOM | Signature | 16/09/1950 | |
| YUGOSLAVIA, FEDERAL REPUBLIC OF | Succession | 12/03/2001 | 27/04/1992 |