The use of the instrument and, above all, the laser-scanner software, allows a detailed digital model of the Roman amphitheater of Tarraco, which has the particularity of conserving a Visigoth and a medieval church on its arena. The acquisition of the digital model is the documental basis for the study and virtual reconstruction of a partially preserved building, and also for the stakeout of a structure built on the hill slope. Finally, it allows the quantification of the monument, in terms of its constructive components or the hypothesis about its capacity and management strategies.