In 1983 he moved to the United States on a scholarship to study at Berklee College of Music in Boston. He was the first student in the school's history to be offered a teaching position upon graduation. While at Berklee, he formed the group Forward Motion with Tommy Smith, Terje Gewelt and Ian Froman.
He soon formed his first trio with Froman and Miroslav Vitous with whom he recorded The Secret for Antilles Records. His second album, The Legend of Tsumi (Antilles) featured Dave Holland and Bob Moses.
In 1987, he won first prize at the Great American Jazz Piano Competition. Since 1987 he has been on the faculty at Berklee where he is Professor of Piano.
Gardony's first album for Sunnyside Records was a critically acclaimed solo piano disc, Changing Standards. His next album, Breakout (Avenue Jazz Records), was released in 1994 and featured Mick Goodrick on guitar as well as George Jinda (talking drum; udu), Satoshi Takeishi (taiko drums) and Stomu Takeishi (electric bass).
Gardony returned to Sunnyside in 2001 with a trio recording, Behind Open Doors which featured Jamey Haddad and John Lockwood. Subsequently, Gardony has recorded four albums with bassist John Lockwood and drummer Yoron Israel, his working trio of nine years: Ever Before Ever After (Sunnyside) in 2003, Natural Instinct (Sunnyside) in 2006, Dig Deep (Sunnyside) in 2008 and Signature Time (Sunnyside) in 2011  Signature Time  also features multi-instrmentalist, vocalist, Stan Strickland on a few tracks as well as drummer Yoron Israel on the vibraphone. His 2013 recording is a solo piano album, Clarity (Sunnyside) In 2015 Gardony released a live sextet album, Life in Real Time (Sunnyside) with Bill Pierce, Don Braden, Stan Strickland, Yoron Israel and John Lockwood. The album was named by the Boston Globe as one of the 10 best jazz albums of 2015 
Among other projects, he has also been involved in violinist Matt Glaser's group, The Wayfaring Strangers, a fusion of bluegrass and jazz. Gardony has performed with the Wayfaring Strangers at numerous venues and festivals, including Symphony Hall with the Boston Pops, with the Utah Symphony in Salt Lake City, and at Merlefest in North Carolina. Gardony has also performed with David "Fathead" Newman at several festivals, and with Eddie Gomez's Per Sempre Quintet. Both Randy Brecker and Dave Liebman have performed as guest soloists with Gardony's group.  Gardony is featured on two Yoron Israel & High Standards albums: Visions – The Music of Stevie Wonder (Ronja, 2012) and This Moment (Ronja, 2015).
Gardony has been praised for his "fluid pianism" in The New York Times and for his uniformly high quality of compositions, harmonic complexity and emotional content which All About Jazz Magazine found to be on par with Bill Evans'. Jazz Review has described him as "a pianist worthy of praise within the highest pantheon of performers". Dave Brubeck called Gardony a "great pianist".
- 1986 The Secret (Antilles)
- 1988 Legend of Tsumi (Antilles)
- 1990 Changing Standards (Sunnyside)
- 1994 Breakout Avenue (Rhino)
- 2001 Behind Open Doors (Sunnyside)
- 2003 Ever Before Ever After (Sunnyside)
- 2006 Natural Instinct (Sunnyside)
- 2008 Dig Deep (Sunnyside)
- 2011 Signature Time (Sunnyside)
- 2013 Clarity (Sunnyside)
- 2015 Life in Real Time (Sunnyside)
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- Laszlo Gardony website
- "Laszlo Gardony | Album Discography | AllMusic". AllMusic. Retrieved 28 August 2016.