 He is the Director of the Italian National Group GNAMPA of the Istituto Nazionale di Alta Matematica Francesco Severi (INdAM).Marcellini received his Laurea Degree in 1971 at the Sapienza University of Rome and made his postgraduate studies from 1971–1973 at the Scuola Normale Superiore in Pisa under the supervision of Ennio De Giorgi.After that he was assistant and finally a lecturer at the University of Florence, in 1981 full professor at the University of Naples and then at the University of Tor Vergata in Rome.