On the afternoon of the 5^th day of the first lunar month, all of the eight communes (including Co Loa Commune and the establishing relations between seven communes) hold the incense offering ceremony at the communal house. At Thuong Temple, village officials and mandarins hold the similar ceremony and revise the king's contributions and achievements. The official festival day, which is on the 6^th of the first lunar month, starts with processions and grand sacrifices- offering ceremony. In early morning, a solemn and splendid procession takes orations from the oration writer's house to the temple. The chief officiant at Thuong Temple has to come up and receive the orations and puts them on the altar. Next to the door of the temple is a pair of life-size pink and white wooden horses. Their harnesses are decorated with phoenix motifs and beautiful gold thread embroideries.
 

The path to the temple is lined with decorative weapons and eight precious votive objects. At that time, the palanquins of the establishing relations between seven communes arrive at Thuong Temple and are put on the yard. The worshipping rituals begin. Votive offerings include incense, flowers, truncated cone-shaped cakes made of sticky rice, fruits, steamed sticky rice, meat, giay cakes and popcorn. According to folk knowledge, the last two things were used by King An Duong Vuong to treat his troops. The rituals last until 12 o'clock. Meanwhile, in the temple, some senior people representing their communes pray to the king for peace and prosperity to their villagers.

Next is the procession to take the god from the temple to the communal house so that he can watch the festivities. This is the biggest procession with the participation of all the palanquins. When reaching the main entrance called Nghi Mon, the palanquins return to their villages. Co Loa's procession and palanquin do the same rituals once more at the communal house. This is the end of the official festival day. From then to the end of the whole festival, there are only duty ceremonies and votive offerings of residential groups, family lines and visitors.

An Duong Vuong Temple Festival has a special procession for the fake king of Nhoi village. On Mount Sai in Nhoi Village is a temple dedicated to Saint Tran Vu, who, according to legends, helps the king drive away evil spirits and build Co Loa Citadel. Every year, on the 12^th day of the first lunar month, the king would go there together with his mandarins to do worshipping rituals.

But because such travelling was quite complicated, King An Duong Vuong asked a local man to impersonate him and held a similar ritual. Later generations put on stage that story. Though this custom is specific for Nhoi Village, it helps to diversify activities of the Co Loa Festival.

The Co Loa Festival has many other fun activities such as human chess, wrestling, cock fighting, swings, rope climbing, card playing, and cheo and tuong singing.

On the final day of the festival, a grand farewell ceremony will be held at the temple. The rituals are the same as in the main festival day. After the rituals, the cult table of god will be returned to the sanctuary. Local people enjoy the god's favour and expect a year of prosperity and protection from the god.