In a speech in Bern on the opening day of his visit, Essebsi, 89, referred to Switzerland having “joined the European Union”, although Switzerland is not - and never has been - a member of the EU.
“Switzerland has an important place in Europe,” the Tunisian president said in the federal parliament building.
“I know that Switzerland joined the European Union rather late but it occupies a significant place there.”
His mistake was immediately picked up by broadcaster RTS and other journalists.
It may have been that Essebsi mixed up the fact that Switzerland joined the United Nations, relatively late, in 2002.
The Tunisian president made another widely reported gaffe when he referred to French President François Hollande as François Mitterand when Hollande paid a visit to Tunis in March 2015.
Essebsi's visit, originally scheduled for last November and the first made to Switzerland by a Tunisian president, aimed to strengthen cooperation on several fronts between Bern and Tunis.
Swiss President Johann Schneider-Ammann congratulated Tunisia for having “traversed the numerous problems of the Arab Spring with a lot of maturity and wisdom”.
He also praised the new Tunisian constitution, adopted in February 2014, that recognizes Islam as the state religion while guaranteeing freedom of belief for all citizens.
The federal government said it had supported moves toward the democratic transition of Tunisia with funding of 80 million francs between 2011 and 2015, following the overthrow of President Zine El Abidene Ben Ali.
Switzerland froze assets in Swiss banks of Ben Ali and his entourage and Bern is still in the process of reinstating the money, claimed by the Tunisian government as ill-gotten gains.
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Bern said delegations from both countries acknowledged “good cooperation on this issue”.
A letter of intent was signed on Thursday between the two countries on the blocked assets issue.
The second day of Essebsi's visit was devoted to economic cooperation and an exchange on vocational training.