The international associations, basic to multilateral relations, characterize the activities of the LCTO for a long time. Even before the foundation of the today's LCTO, the City of Luxembourg has been represented in the "Association des villes belges et luxembourgeoises pour attirer les touristes étrangers".

Nowadays the LCTO is member of the "European Cities Marketing" (ECM) and the "Association Internationale des Villes Francophones de Congrès" (AIVFC).

Furthermore the LCTO signs responsible for the tourist part of the cross-border city network QuattroPole (Luxembourg, Metz, Saarbrücken, Trier), of which the City of Luxembourg is member.

The LCTO participates in the different promotional activities, launched by these international associations.

On a national level, the LCTO is member of the Luxembourg National Tourist Office, the privileged partner for worldwide promotion campaigns and shareholder in Luxembourg Congrès. The LCTO is also represented in the Association of the Castles in Luxembourg, the "Agence luxembourgeoise d’action culturelle" and the National Tourist Commission.

On a city level, the LCTO takes part in the municipal working groups "signalétique", "plan lumière", "i-phone", "commerce", "image de marque", "comité de pilotage événementiel", "gestion de l’espace public" and "Cité Cercle".