Part of the Norman church remains, but it has been greatly modified over later centuries.
The original Priory Church was built in local yellow Triassic sandstone, with a long vaulted nave, massive piers, and a notably ornamented west entrance doorway with zigzag and lozenge patterns, dating from the early 12th century.
These parts remain.
However, later extensions and modifications have used other varieties of stone in other architectural styles, with the result that the whole church has been described as "an extraordinarily disjointed building."

The main central tower of the original church collapsed in a storm in 1701, destroying the transepts.
A new wall was then built at the eastern end of the nave, and its western end built up to form a new tower, designed "in an amusingly rustic classical idiom".
This was completed in 1706 under the ministry of Thomas Chest, who was vicar from 1701 to 1740.
In 1841, through the influence of Edward Copleston, Bishop of Llandaff, who lived locally, the aisles were removed, and the eastern end, crossing and transepts were rebuilt.
Further work partly to restore the Norman character of the nave was begun in 1890, but was abandoned unfinished in 1913.

The church contains two fonts, one of Norman origin and the other from the 15th century.
There are several notable tombs and memorials, including that of Henry Somerset, 2nd Earl of Worcester, and the Jacobean tomb of local benefactor Margaret Cleyton with her two husbands and 12 children.
It also contains the tomb of Henry Marten, signatory to King Charles I's death warrant, who was imprisoned in Chepstow Castle until his death in 1680.
His memorial includes an acrostic epitaph.

The organ, one of the few in the country with pipework dating from the early 17th century, was originally made for Gloucester Cathedral (possibly by the Dallam family).
It was moved to Bristol Cathedral in 1663 and then to Chepstow possibly as early as 1685, and certainly by the 18th century.
It was rebuilt and expanded in 1906, and has undergone a variety of maintenance and repair work since.
Eight of the ten bells in the tower date from 1735 and were made in Chepstow by William Evans; the two lightest bells were added in 1959 and were cast by John Taylor & Co.. The original clock mechanism was also made locally in the 18th century, and kept time until replaced by an electric clock in 1965.
Part of the Norman church remains, but it has been greatly modified over later centuries. The original Priory Church was built in local yellow Triassic sandstone, with a long vaulted nave, massive piers, and a notably ornamented west entrance doorway with zigzag and lozenge patterns, dating from the early 12th century. These parts remain. However, later extensions and modifications have used other varieties of stone in other architectural styles, with the result that the whole church has been described as "an extraordinarily disjointed building."
The main central tower of the original church collapsed in a storm in 1701, destroying the transepts. A new wall was then built at the eastern end of the nave, and its western end built up to form a new tower, designed "in an amusingly rustic classical idiom". This was completed in 1706 under the ministry of Thomas Chest, who was vicar from 1701 to 1740. In 1841, through the influence of Edward Copleston, Bishop of Llandaff, who lived locally, the aisles were removed, and the eastern end, crossing and transepts were rebuilt. Further work partly to restore the Norman character of the nave was begun in 1890, but was abandoned unfinished in 1913.
The church contains two fonts, one of Norman origin and the other from the 15th century. There are several notable tombs and memorials, including that of Henry Somerset, 2nd Earl of Worcester, and the Jacobean tomb of local benefactor Margaret Cleyton with her two husbands and 12 children. It also contains the tomb of Henry Marten, signatory to King Charles I's death warrant, who was imprisoned in Chepstow Castle until his death in 1680. His memorial includes an acrostic epitaph.
The organ, one of the few in the country with pipework dating from the early 17th century, was originally made for Gloucester Cathedral (possibly by the Dallam family). It was moved to Bristol Cathedral in 1663 and then to Chepstow possibly as early as 1685, and certainly by the 18th century. It was rebuilt and expanded in 1906, and has undergone a variety of maintenance and repair work since. Eight of the ten bells in the tower date from 1735 and were made in Chepstow by William Evans; the two lightest bells were added in 1959 and were cast by John Taylor & Co.. The original clock mechanism was also made locally in the 18th century, and kept time until replaced by an electric clock in 1965.
Priory Church of St Mary, Chepstow