The baptistery was built in the eastern area of the ancient city of Nocera in Campania. For its construction, several Roman-era buildings were demolished, whose mosaic floors are still visible in archaeological excavations inside and outside the monument. These were most likely residential buildings (domus) from the height of the Imperial period; the majestic mosaics testify to the wealth of the Roman city.

The baptistery has been the subject of numerous archaeological excavations since the 1950s, which have helped to delineate the monument's origins and development.