This article presents changes which occurred in the urban structure of Rome in the Baroque period. The initiator of the redevelopment of this city, dictated mainly by ideological concerns, was Pope Sixtus V who commissioned one of the greatest creators of that epoch – architect Domenico Fontana – to redesign the urban structure. The redevelopment was expected to become a symbol of the popes’ return to Rome as well as to improve transport between the most important basilicas in the city: S. Trinita dei Monti, S.M. Maggiore, S. Giovanni in Laterano and S. Croce in Gerusaleme. The construction of the most important urban enclosures in that period – the square outside St. Peter’s Basilica, Navona Square, the Spanish Stairs and Del Popolo Square – was planned then, too. Changes which occurred in the tissue of Rome in relation to Fontana’s plan are still legible in the urban layout of the city, whereas squares designed at that time make the centre of cultural and tourist life these days.