The biggest jazz event in Prague will once again take place at Karlovo náměstí and is a celebration of International Jazz Day, which falls on April 30. Come to one of the first open-air concerts of 2026 and discover a wealth of music. International Jazz Day has been celebrated around the world at the end of April since 2012, with various concerts and commemorative events taking place on that day — and thanks to the team behind the Mladí ladí jazz festival, Prague has its own celebration as well. International Jazz Day has existed under the patronage of UNESCO and Prague is securing its place on the jazz map of Europe also thanks to this unique city festival, which is the largest jazz celebration in the Czech Republic on that day. Fb event