Born in Fano, Marche, Serafini started his career at Vis Pesaro.
In June 2007, he signed a 3-year contract with Serie B side AlbinoLeffe on free transfer.
[4] In summer 2010 he return to AlbinoLeffe but he doesn't play any games and in January 2011 he joined Atletico Roma F.C.
In summer 2011 his club did not participate in any professional league and dissolves, and so Mattia joined Prato.
[6] On 18 June 2012 Serafini was banned for 3 years and 6 months due to 2011–12 Italian football scandal.