Born in 1951 in Pistoia, Italy. In 1977 he graduated from the Facoltà di Architettura di Firenze, where he collaborated with scholar Remo Buti from 1980 to 1992. In 1980 he founded a firm with Alberto Casciani, for the design and the production of experimental objects and furniture, called Studio Stilema. The studio worked on many research projects in the fields of industrial design, decoration, graphic design, exhibition and interior design; in the early eighties Mariani took part to many exhibitions and events in the amazing tradition of Italian neo-design.
In 1986, with a group of architects (P.Caramia, D.Carani, M.Castelvetro M.Corrado, D.Donegani, S.Giovannoni, M.Iosa Ghini, G.Venturini) Mariani launched the Bolidismo.
Since 1990, Mariani’s professional activity, based in a studio in Montecatini Terme, has focused on interior design and architecture.