More than 100,000 association delegates attended events in Berlin last year, ahead of Barcelona with 81,933, Paris with 73,872 and Bangkok with 58,007.
Berlin has attracted 517,943 incoming association events visitors over the past decade, with numbers tripling from 30,850 delegates in 1999 to 106,171 in 2008.
Berlin Convention Office director of conventions Heike Mahmoud said the German capital had developed into a "convention metropolis" over the past decade.
"The city offers organisers the most up-to-date hotel landscape in Europe, excellent value for money, renowned convention centres like the ICC Berlin and unusual locations," she said. "The latest ICCA statistics confirm the positive response to this diversity - a resounding success for the German capital and Berlin Convention Office."