During the mid-80s while in Chicago, he was associated with the birth of house music. He acted as an agent for many of the young Chicago house acts. Such artists included top names like Marshall Jefferson and Adonis. He organized their first gigs in New York and London, at venues like the Paradise Garage and the Ministry of Sound.
Katsis later moved to Los Angeles and became a partner in talent and entertainment agency The Firm. At the agency he helped the careers of Backstreet Boys, Korn, Enrique Iglesias, 30 Seconds to Mars, Snoop Dogg, One Direction, Audioslave, Limp Bizkit, Stained and others.
Katsis has also strategized the launch of many arena and stadium concert tours such as the Backstreet Boys “Into The Millennium Tour” in 1999. At that time, the 26 truck tour sold a Ticketmaster record of 735,000 tickets in less than one hour.
In 2008 through 2014, Mr. Katsis – along with partners Jeff Kwatinetz and Rich Frank – founded Prospect Park Entertainment. During that time he continued his work managing the music careers of top artists like The Smashing Pumpkins, Jane’s Addiction, Korn, Audioslave, Ice Cube and the Backstreet Boys.
Currently Mr Katsis is a partner at Deckstar in Los Angeles, where he manages The Smashing Pumpkins, Jane's Addiction, Culture Club(co-managed with Paul Kemsley), The Joy Formidable, and others.
Chicago house music influenced the development of Electronic Dance Music (EDM). The combined record sales of artists Katsis has been involved with in management total over 300 million albums. 
- "Exclusive: Did Smashing Pumpkins Break Up Power Managers Jeff Kwatinetz and Peter Katsis?". Retrieved 2 December 2015.
- "Executive Profile - Peter Katsis". Retrieved 2 December 2015.
- Burrough, Brian (July 31, 2002). "Ovitz Agnoistes". Vanity Fair (Vanity Fair). Retrieved 16 December 2015.