| Country | Action | Action Date | Effective Date |
|---|
| AFGHANISTAN | Membership | | 01/01/1958 |
| ALBANIA | Membership | | 01/01/1958 |
| Antilles | Extension | 01/01/1958 | |
| ARGENTINA | Membership | | 01/01/1958 |
| AUSTRALIA | Membership | | 01/01/1958 |
| AUSTRIA | Membership | | 01/01/1958 |
| Bahrain | Extension | 01/01/1905 | |
| BELGIUM | Membership | | 01/01/1958 |
| BOLIVIA | Membership | | 01/01/1958 |
| BRAZIL | Membership | | 01/01/1958 |
| BULGARIA | Membership | | 01/01/1958 |
| BURMA | Membership | | 01/01/1958 |
| CAMBODIA | Membership | | 01/01/1958 |
| CANADA | Membership | | 01/01/1958 |
| CEYLON | Membership | | 01/01/1958 |
| Channel Islands | Extension | 01/01/1905 | |
| CHILE | Membership | | 01/01/1958 |
| CHINA | Membership | | 01/01/1958 |
| COSTA RICA | Membership | | 01/01/1958 |
| CUBA | Membership | | 01/01/1958 |
| CZECHOSLOVAKIA | Membership | | 01/01/1958 |
| DENMARK | Membership | | 01/01/1958 |
| DOMINICAN REPUBLIC | Membership | | 01/01/1958 |
| ECUADOR | Membership | | 01/01/1958 |
| EGYPT | Membership | | 01/01/1958 |
| ETHIOPIA | Membership | | 01/01/1958 |
| FINLAND | Membership | | 01/01/1958 |
| FRANCE | Membership | | 01/01/1958 |
| GERMANY FEDERAL REPUBLIC | Membership | | 01/01/1958 |
| GREECE | Membership | | 01/01/1958 |
| GUATEMALA | Membership | | 01/01/1958 |
| HAITI | Membership | | 01/01/1958 |
| HONDURAS | Membership | | 01/01/1958 |
| ICELAND | Membership | | 01/01/1958 |
| INDIA | Membership | | 01/01/1958 |
| INDONESIA | Membership | | 01/01/1958 |
| IRAN | Membership | | 01/01/1958 |
| IRAQ | Membership | | 01/01/1958 |
| IRELAND, REPUBLIC OF | Membership | | 01/01/1958 |
| Isle of Man | Extension | 01/01/1905 | |
| ISRAEL | Membership | | 01/01/1958 |
| ITALY | Membership | | 01/01/1958 |
| JAPAN | Membership | | 01/01/1958 |
| JORDAN | Membership | | 01/01/1958 |
| KOREA | Membership | | 01/01/1958 |
| Kuwait | Extension | 14/03/1956 | |
| LAOS | Membership | | 01/01/1958 |
| LEBANON | Membership | | 01/01/1958 |
| LIBERIA | Membership | | 01/01/1958 |
| LIBYA | Membership | | 01/01/1958 |
| LUXEMBOURG | Membership | | 01/01/1958 |
| MEXICO | Membership | | 01/01/1958 |
| MONACO | Membership | | 01/01/1958 |
| MOROCCO | Membership | | 01/01/1958 |
| NEPAL | Membership | | 01/01/1958 |
| NETHERLANDS THE | Membership | | 01/01/1958 |
| New Guinea | Extension | 01/01/1958 | |
| New Guinea | Reservation | 01/01/1958 | |
| NEW ZEALAND | Membership | | 01/01/1958 |
| NICARAGUA | Membership | | 01/01/1958 |
| NORWAY | Membership | | 01/01/1958 |
| PANAMA | Membership | | 01/01/1958 |
| PARAGUAY | Membership | | 01/01/1958 |
| PERU | Membership | | 01/01/1958 |
| PHILIPPINES | Membership | | 01/01/1958 |
| POLAND | Membership | | 01/01/1958 |
| PORTUGAL | Membership | | 01/01/1958 |
| Qatar | Extension | 01/01/1905 | |
| ROUMANIA | Membership | | 01/01/1958 |
| SALVADOR | Membership | | 01/01/1958 |
| SAUDI ARABIA | Membership | | 01/01/1958 |
| SOUTH AFRICA | Membership | | 01/01/1958 |
| SOVIET UNION | Membership | | 01/01/1958 |
| SPAIN | Membership | | 01/01/1958 |
| St Vincent | Extension | 01/01/1905 | |
| St Vincent | Reservation | 01/01/1905 | |
| SUDAN | Membership | | 01/01/1958 |
| SUDAN | Accession | 15/03/1956 | |
| SWEDEN | Membership | | 01/01/1958 |
| SWITZERLAND | Membership | | 01/01/1958 |
| SYRIA | Membership | | 01/01/1958 |
| THAILAND | Membership | | 01/01/1958 |
| Trucial States | Extension | 01/01/1905 | |
| TUNISIA | Membership | | 01/01/1958 |
| TURKEY | Membership | | 01/01/1958 |
| UNITED KINGDOM | Membership | | 01/01/1958 |
| UNITED STATES OF AMERICA | Membership | | 01/01/1958 |
| URUGUAY | Membership | | 01/01/1958 |
| VENEZUELA | Membership | | 01/01/1958 |
| VIETNAM | Membership | | 01/01/1958 |
| West Indies | Extension | 01/01/1958 | |
| YEMEN | Membership | | 01/01/1958 |
| YUGOSLAVIA | Membership | | 01/01/1958 |