Van Buuren began his DJ career at club Nexus in Leiden, where he learned to play long DJ sets, which were regularly six to seven hours per set. During school holidays he played more than four times a week. In 1999, he met Dave Lewis who introduced him as a DJ in England and the United States. His DJ career accelerated, entering the DJ magazine Top-100 in November of 2001 at Number 27. He has played in more than 25 different countries and can often be found on the main stage at big summer festivals. Recently, Van Buuren played a record-breaking nine-hour set for Dancetheater in The Hague (Holland). In the United Kingdom one can see him perform regularly at Passion (resident 2002), Godskitchen, Gatecrasher, Slinky, Peach and Golden.

In the United States, he has a residency at Glow in Washington D.C. and has played in Boston, Chicago, Atlanta, Denver, New York City, and Los Angeles. He has also regularly appeared at Amnesia on the island of Ibiza.

Lately, Van Buuren has been working hard on his DJ career, performing an average of more than two performances per weekend. According to him, "The fans and the public are the most important thing for a DJ." Because he strongly believes in the importance of his fans, he can be seen signing his autograph on virtually anything: vinyl records, flyers, t-shirts, body parts, and mobile phones.

On April 12th of 2006, Van Buuren began a Canadian tour with a performance in Winnipeg, Manitoba, Canada. This was his first appearance in the centrally located Canadian city. Despite a Wednesday booking, the venue was filled to capacity with fans eager to see Armin perform. Throughout his set Armin could be seen signing autographs for his eager fans.

On November 11, 2006 he had a live performance called Armin Only in Ahoy Rotterdam for the second time (after Nov 12, 2005) with a 9 hour solo set, where he performed to over 11.000 fans.