Born in Siracusa in 1929, Marchegiani has lived and worked in Livorno, Rome, Bologna and Milan. He started exhibiting in Livorno in 1958, was a member of “Gruppo 70” in Florence and participated in the VIII Quadriennale in Rome. In the 1960s Marchegiani exhibited at Galleria Apollinaire in Milan and Galleria Obelisco in Rome and, from 1969, taught at the Accademia di Belle Arti of Urbino, later appointed Chair of Painting there.
Awarded the Gold Medal at the San Marino Biennale in 1967, he was invited to participate in the Venice Biennale three times, in 1968, 1972 and 1986. He currently lives in Pianoro, in the province of Bologna.