Marco Pacassoni was born June 12, 1981, in Fano, on Italy's Adriatic coast, and grew up attending the town's long-running summer jazz festival, an early and formative exposure to the music. He studied percussion at the Conservatorio Gioachino Rossini in Pesaro before winning a scholarship to Berklee College of Music in Boston, where he graduated with honors in 2004 in Professional Music, studying vibraphone and marimba under Gary Burton, Ed Saindon and Victor Mendoza. He has been active as a performer since 1999, starting in the group Vibrafonia, and returned to Italy to build his career from Fano, where he is based today.

In 2005 he won the "Talento jazz del panorama italiano" award at the Chicco Bettinardi Competition, part of the Piacenza Jazz Festival, recognizing him as one of Italy's leading young jazz talents. He formed the Marco Pacassoni Quartet, and its debut, Finally... (2011, Groove Master Edition), paired his vibraphone and marimba with Enzo Bocciero on piano, Amik Guerra on trumpet and flugelhorn, and a rhythm section including percussionist Alex Acuna. The quartet's second album, Happiness (2014, Alfa Music), featured a guest duet from Grammy-winning pianist Michel Camilo, with Lorenzo De Angeli on bass and Matteo Pantaleoni on drums joining Bocciero. A third quartet album, Grazie (2017, Nasswetter Music Group), split its ten original compositions evenly between Pacassoni's and Bocciero's writing and was dedicated to Pacassoni's late father, Giorgio Pacassoni, in gratitude for his support of his son's music career; Discogs tags the record Contemporary Jazz, Post Bop and Latin Jazz.

In 2018 Pacassoni turned to a different kind of project, Frank & Ruth (Esordisco), a vibraphone-and-marimba tribute to Frank Zappa named for Zappa and his longtime percussionist Ruth Underwood. Billed as the Marco Pacassoni Group, the record set Pacassoni's mallets against Alberto Lombardi's guitars and Enzo Bocciero's keyboards, with drummer Gregory Hutchinson, vocalist Petra Magoni and a track list running from Zappa originals such as "The Black Page" and "Peaches En Regalia" to a version of Oliver Nelson's jazz standard "Stolen Moments." In 2021 he released Hands & Mallets (Da Vinci Jazz), a duo record with Bocciero marking, per the label's own description, seventeen years of collaboration between the two musicians, built almost entirely around new original material.

His most substantial recent project reunited him with two prominent American jazz musicians: Life (2022, Giotto Music), credited to the Marco Pacassoni Trio featuring John Patitucci and Antonio Sanchez, with Patitucci on acoustic and electric bass and Sanchez on drums alongside Pacassoni's vibraphone and marimba. Genre-tagged Jazz and Contemporary Jazz on Discogs, the album was mixed by Red Battistelli, mastered by Grammy-winning engineer Gene Paul, and recorded by Aaron Nevezie. Beyond his own leader catalog, Pacassoni has worked as a session and touring percussionist for Italian popular artists including Ornella Vanoni and the singer-songwriter Bungaro, with whom he has two Discogs-verified studio credits, Entronauta (2021) and the 2026 release Fuoco Sacro.

Pacassoni teaches percussion at the Liceo Rinaldini in Ancona and harmony at the Zero Crossing Academy of Music in Pesaro, has taught vibraphone and marimba at the University of Texas at San Antonio and the Universita di Urbino, and gives international masterclasses. In 2014 he published a harmony and composition text, Quasi Quasi Scrivo Una Canzone. He is endorsed by Adams vibraphones and marimbas, Zildjian cymbals, Vic Firth mallets and sticks, and Gon Bops percussion.

Pacassoni's core sound is a working small-group jazz vocabulary built around vibraphone and marimba as lead voices rather than as a rhythm-section color, a lineage traceable to his own teacher Gary Burton. His original-composition albums with the Marco Pacassoni Quartet move between contemporary post-bop writing and Latin jazz rhythm, reflecting his stated interest in Latin percussion and his time playing with Latin-jazz specialists Alex Acuna and Horacio "El Negro" Hernandez. His most unusual project, Frank & Ruth, translates Frank Zappa's notoriously dense, meter-shifting compositions into a mallet-and-guitar chamber format, a deliberate departure from his more mainstream-jazz quartet work that nonetheless still closes with a straight-ahead jazz standard, Oliver Nelson's "Stolen Moments." Duo and trio settings recur throughout his catalog, from Hands & Mallets' stripped-down vibraphone-and-piano writing with Enzo Bocciero to the Patitucci/Sanchez trio session Life, where the writing leaves more open space for each player.