This temple of Serapis was built by Egyptian merchants to the name of god Serapis and located on the Commercial Agora near the western gate. It is a recorded fact that Ephesus had a very strong commercial relationship with the importnat port city of Egypt, Alexandria. During these ancient times Egypt was the biggest producer of wheat. They exchanged wheat with other commercial items from Ephesus and other Ionian cities.

There are certain indications suggesting that the temple was never finished fully. It is estimated that the construction of the temple was started in the 2nd century A.D.

There was a 24m. wide and 160m. long stoa (a walk-way surrounded by a wall on one side and columns on the other. It is covered usually by a roof) leading the way to the temple on the western gate direction of the Agora. There is also another entrance into the temple from the south-west corner of the Agora through stairs.

The main structure of the Serapis temple was located to the southern border of a large courtyard surrounded by the columns. The 29m. wide holy square where the cult of the temple was kept had very thick walls to hold the heavy stone roof. The entrance to the temple was supported by giant single-piece, 1.5m. in diameter, with 57 tones granite columns. The main door was made up of a very thick metal. This huge door was opened and closed by the help of the wheels located underneath.

There is a statue found inside the temple made by using the Egyptian granite. Also some inscriptions found inside the temple indicate that the temple was constructed for those who believed in Serapis. In Ephesus Museum there is a monument on which the main Goddess of Ephesians, Artemis, and the principal god of Egypt, Serapis, take place together with garland as a symbol of peace.

The Temple of Serapis was converted to a church during the following Christian period. There are also remains of a baptisterium in the eastern corner of the Temple.