Portici is on the slopes of the west side of Mount Vesuvius and occupies a small portion of territory along the coast of the Gulf of Naples. It borders with the municipality of San Giorgio a Cremano and with the districts of Naples, San Giovanni a Teduccio and Barra to the north, with Ercolano to the south and east, while with the Tyrrhenian Sea to the west.

Portici has a small gulf called the Granatello. The name derives from the fact that in ancient times, from the Villa of Portici up to the Convent of St Mary, in the eighteenth century, there were many pomegranate plants.