Switzerland opened a consulate in Lisbon in 1817, which was upgraded to a consulate general in 1874. A second consulate was added in Porto in 1896. The first agrément for a Swiss diplomat, on 7 March 1919, was followed by a Swiss diplomatic chancery in the Portuguese capital in 1936, which was upgraded to a legation in 1945 and to an embassy in 1959. Portugal established its first consulate in Switzerland in Geneva in 1855. The Portuguese legation in Bern, opened in 1892, was upgraded to an embassy in 1959.
The membership of both countries in the European Free Trade Association (EFTA) from 1960 to 1985 fostered their bilateral relations. From 1963 to 1975, the Swiss Confederation represented Portuguese interests in Senegal.
In 2016, President Marcelo Rebelo de Sousa paid a state visit to Switzerland, which was followed by a state visit to Lisbon by President Doris Leuthard in 2017.
Portugal, Historical Dictionary of Switzerland (de, fr, it)
Diplomatic Documents of Switzerland, Dodis