Hosseini was born in Tehran, Iran, and received his master's degree and Doctor of Music degree (DMA) in Composition from Saint Petersburg State Conservatory, named after N. A. Rimsky-Korsakov. His major teachers include Farhad Fakhreddini, Prof. Alexander Minatsakanian, Prof. Nigel Osborne and Prof. Sergei Slonimsky in composition, and Professor Tatiana Bershadskaya in Musicology. His early musical experiences included from 1998–2001, where he studying music theory, Persian music and composition with Farhad Fakhreddini in Tehran. Hosseini then entered the Saint Petersburg State Conservatory in 2001 where he under the guidance of Prof. Tatiana Bershadskaya studied musicology and composition with Prof. Mnatsakanian and continued postgraduate course with the composer Sergei Slonimsky. Mehdi Hosseini completed a composition course from the University of Music and Performing Arts, Vienna in 2007 during the summer courses at Mürzzuschlag, Austria where he studied with Nigel Osborne.
Hosseini’s compositions include works for large orchestra, chamber orchestra, and various ensembles and has been performed and recorded by orchestras and ensembles such as the St. Petersburg State Philharmonic Symphony Orchestra, the Saint Petersburg Academic Symphony Orchestra, Symphony Orchestra of the Opera and Ballet Theatre of the St. Petersburg State Conservatory, North-Ossetian State Symphony Orchestra, Ensemble intercontemporain, Namascae, Lemanic Modern Ensemble, PluralEnsemble, Ensemble Proton Bern, Studio for New Music Ensemble, Moscow Contemporary Music Ensemble, GAMEnsemble and more. His works have been published by the Compozitor Publishing House (Russia), and Donemus (Netherlands).
In the last few years, He was the focus of attention in Russia as a composer. and his works are performed during such festivals as St. Petersburg Musical Spring, Contemporary East and West, Contemporary Past, A Reverse Perspective, Trajectories of Petersburg Avant-Garde, Sound Ways, Moscow Autumn, Moscow Actual Music Festival “Another Space” and others. His music is played in Mariinsky Theatre, Saint Petersburg and Moscow Conservatories, Saint Petersburg and Moscow Philharmonics.
Mehdi Hosseini made an invaluable contribution to the development of the St. Petersburg cultural scene in 2011 when he opened the Saint Petersburg Contemporary Music Center “reMusik.org” and in 2013, he founded the St. Petersburg International New Music Festival.