This report presents the conservation programme of the Atrium of the Capitoline Museum in Rome and of the collection of classical sculptures housed on the ground floor. The work was carried out leaving the site open to the public and various initiatives were organized to inform visitors. New equipment was specially designed for this project: planning, documentation, historic and archival research gave the required information to programme the intervention. Cleaning was carried out using atomized water and mechanical tools; lime-based materials were used for consolidation, stuccoing and protection. Following the conservation intervention a maintenance programme is currently being implemented.