St Margaret Marlos Church is situated within an irregularly shaped churchyard, bounded by a road on its south side. During the medieval period it was a chapelry belonging to the Deanery of Carmarthen. By 1833 Pendine was a parish, and its living was a discharged rectory annexed to Llandawke. In 1998 the church was a parish church belonging to the rural Deanery of St Clears. A fragment of pedestal from a churchyard cross was visible in the churchyard in 1912. The Moravian chapel (NPRN 12601), some 70m to the south-south-east, was built around 1770, on land donated by Mrs Lloyd, grandmother of Sir Thomas Lloyd (member for Cardigan in 1880), who spent much time at Great House (NPRN 17402). The land was donated on condition that there should not be service in the chapel when there was service in the church. Around this time the Rees family of Great House attended the Sunday service at the chapel, as well as the church service. It was then usual for an evening service to be held the Saturday before Sunday communion (the same was done before communion at the chapel). In 1873 Mr Saunders, Big House (NPRN 17097) reportedly donated a piece of ground for extension of the churchyard.

The church is a Grade II* listed building, constructed of limestone rubble. It consists of three-bayed nave, two-bayed chancel, south porch, three-storeyed tower, transeptal vestry and organ chamber (north of chancel) and boilerhouse (east of vestry). Medieval openings are of Old Red Sandstone and limestone. Other openings are of grey oolite (1869) and yellow oolite (1891). The nave may date to the thirteenth century. A stoup with two-centred head and plain square bowl may be fourteenth century in date. The chancel, which formerly had two choir recesses, is thought to be fourteenth century in date. There is a fourteenth century two-light window in its east wall. North of the window is a plain, two-centred aumbry. The church had a bell in 1552. The chancel north and south wall windows are thought to be fifteenth century. The porch dates to the fifteenth century. The tower is thought to date to around 1600, and is small and slender shape. In 1861 the church was described as consisting of chancel, nave, west tower and south porch. Before 1869, tombs to the Rees and Saunders families were located to the left (Price) and right (Saunders) of the communion table (within the rails). The church was restored in 1869, to the designs of John Pritchard, Llandaff. The two tombs were removed and two upright memorial stones to the families placed against the external south wall. He replaced the chancel arch (described in 1880 as having formerly been so small that the voice of the clergyman could not be heard clearly from the chancel), and re-roofed the tower with a saddleback roof (thought to be a copy of the original). The nave was re-fenestrated and its doors rebuilt at this time. The porch door was rebuilt and the chancel side windows were unblocked. The church was re-roofed, re-floored and re-plastered. The boilerhouse and vestry and organ chamber date to 1891, and a section of the churchyard wall was removed to make way for them. A lean-to storehouse, positioned between the nave wall and organ chamber west wall, was demolished in the 1990s.

Sources include:
Cadw, Listed Buildings Database
Cambria Archaeology, 2000, Carmarthenshire Churches, gazetteer, 48
Curtis, M, 1880, The Antiquities of Laugharne and Pendine and their Neighbourhoods: Carmarthenshire, Amroth, Saundersfoot, Cilgetty, Pembrokeshire, South Wales (1880)

N Vousden, RCAHMW, 6 March 2013