He composes, sings and plays lead and rhythm guitar.

Mongrain was a session and touring guitarist for the Canadian metal bands Cryptopsy (2005), Gorguts (2000), Alcoholica (2004) and Capharnaum (2003).

In addition to the metal genre, Mongrain plays guitar with several Quebec artists including Dan Bigras, Breen Leboeuf, Bruno Pelletier for the musical Dracula - Entre l'amour et la mort among others and played with more than 80 different formations, bands in numerous genres from Blues to rock to hip-hop to prog to metal, etc.

Mongrain has a bachelor's degree in Jazz Interpretation at University of Montreal and teaches jazz and pop guitar and theory courses at the Cégep régional de Lanaudière, Joliette Campus.

[2] In 2020, Mongrain contributed guitar to Big Scenic Nowhere's Lavender Blues EP.