He started photographing during the ’80s, undertaking an educational path strongly influenced by American landscape photography, in particular of Robert Adams, Lewis Baltz, Stephen Shore. In 1995 he took part to the project promoted by the Province of Milan “Archivio dello Spazio”, a wide photographic analysis of the contemporary landscape, in which he took part again in 1997 together with Antonio Fortugno.  Ongoing from 1994, the collaboration with Antonio Fortugno represents the start of a solid and long-lasting artistic duo that goes on until 2006, giving birth to the creation of many important works and researches that are still central to Andreoni’s interest.

His works have been presented in many individual and group shows. Among the most important Da Guarene all’Etna, in the various editions set up at Chiesa del Carmine in Taormina (1999), at Padiglione Italia of the 2002 Venice Biennial, at Fondazione Sandretto Re Rebaudengo in Turin (2003 and 2009); L’idea di paesaggio nella fotografia italiana dal 1850 ad oggi, Galleria Civica of Modena (2003); Landscape as metaphor, Ursula Blickle Stiftung in Kraichtal, (Germany); La dolce crisi at Villa Manin Centro d’Arte Contemporanea in Passariano (UD); The Pantagruel Syndrome, for T1-Torinotriennale tremusei (2005); Deutsche Bank Collection at the Deutsche Bank in Milan (2007); Fatto bene! at Centro per l’Arte Contemporanea Luigi Pecci in Prato (2008); Terzo Paesaggio at GAM in Gallarate (2009).

Along with the photographic activity, Andreoni has been teaching for many years: he has taught courses on Photography and History of photography in various institutions, such as the Scuola di Specializzazione in Storia dell’Arte of the Università Cattolica in Milan, the Università degli Studi dell’Insubria in Varese, the Naba (Nuova Accademia di Belle Arti) in Milan and the Accademia di Belle Arti in Bologna. He regularly holds workshops and since 2008 he curates the project of artist residencies related to the Mountain Photo Festival.

From 2013, he is teaching at the Accademia Carrara di Belle Arti of Bergamo.