Maria started acting on stage at a young age with Ċentru Żgħażagħ Antonjani of Valletta, along with other budding young actors, such as her brother Paul Mintoff, Hector Bruno, Joseph Debono and others.
In 1982 she joined M.A.S.K. the resident theatrical company at the Catholic Institute Floriana. Under the direction of renowned stage personalities such as Joe Quattromani, Alfred Mallia, John Suda and Carmel S. Aquilina she took part in many theatrical productions many of which were original works penned by the late Patri Ġwann Abela OFM.
Maria took leading roles in many productions, such as Wenżu u Rożi (1983), Jien Hu (1984), Skapin by Moliere (1984), Ġrajjietna (1985), Qalbiena (1985), Il-Ħadd fuq il-Bejt by Francis Ebejer, (1985), Fantasart (1987) Tamietna (1989), L-Imrewħa by Carlo Goldoni (1989) and Il-Ħanut tal-Kafe by Carlo Goldoni (1990), to name a few.
She also took part in other productions such as It-Tfal tal-Papà (Klabb Siparju 1982 at the Manoel Theatre), Auschwitz (SDMU 1986 at University Auditorium) and other satirical productions, such as Mar-Re ma Tgħidx Le (1985) and Hawn iċ-Ċirku(1986).