In ancient Rome, gladiator fights were very popular. The places where these shows took place were called amphitheaters, due to the particular shape of the elliptical building. Amphitheaters were widespread, and in each city, one or more of these buildings was present. This paper describes the virtual reconstruction of the acoustics of the amphitheater Avella, close to Naples, Italy. This amphitheater was discovered a few decades ago and was only partially rebuilt. Today, it is used for musical performances during the summer season mainly. The plan of the building is elliptical, and the dimensions of the arena are 35 m for the minor axis and 65 m for the major axis. Acoustic measurements were performed in the current state with an impulsive sound source and the acoustic parameters were obtained according to the ISO 3382 standard. Subsequently, from the dimensions of the current state and in analogy with the architecture of other amphitheaters existing today, a virtual reconstruction of the original shape was performed. The virtual model was developed with the architectural acoustics software Ramsete in order to obtain the acoustic characteristics of the amphitheater as it was in Roman times. In particular, the spatial distribution of the acoustic characteristics on the steps where the audience was seated is described and discussed.