Proserpina's most distinctly Roman honor is not a temple but a manner of worship imported wholesale from Greek southern Italy. Rome kept a priestess of Ceres, the sacerdos Cereris, drawn by long custom from the Greek cities of Naples or Elea specifically to perform the rites graeco ritu, in the Greek manner, and those rites addressed Ceres and Proserpina together as the mother and the carried off daughter, following the model of Demeter and Persephone at Eleusis rather than any older native Italian pattern. Cicero, who knew the priesthood at first hand, praised the mysteries of Ceres as among the finest things Greece ever gave to the wider world, and Rome's own version, centered on Proserpina's descent and return, kept Greek liturgical language and Greek personnel rather than translating the cult into ordinary Latin custom.
A separate and older strand of her Roman cult addressed her jointly with Dis Pater rather than with her mother. In 249 BCE, after the Sibylline Books were consulted following a run of bad omens during the First Punic War, Rome established an altar to Dis Pater and Proserpina in the Tarentum, a low ground on the Campus Martius, and held nocturnal games there, the Ludi Tarentini, later folded into the recurring Ludi Saeculares that marked the passing of a Roman generation. Where the Ceres based rite ran through a Greek priestess speaking Greek, the Tarentum altar and its games were a Roman state institution addressing the underworld pair directly in Roman terms. Proserpina therefore reached Roman religious life through two distinct channels at once, one borrowed intact from Magna Graecia and one native to Roman civic religion, meeting only in the goddess herself.