St Michael's Church is situated within a rectangular churchyard on the north side of the Blaenffos to Crosswell road. The site may be medieval in origin. The benefice, in common with some other churches in the hundred of Cemais, was held in multiple patronage of the freemen of the parish (a Welsh firm of ecclesiastical tenure). The original churchyard was curvilinear, but it was subsequently remodelled. The original churchyard's original form is visble as a low earthwork. In addition a larger curvilinear outer enclosure boundary has been identified surrounding the churchyard on its west, north and east sides. The Church was first mentioned in the Taxatio of 1291. The church may have replaced a medieval precursor of thirteenth-century date, a possible earlier dedication to St Meugan, the present dedication of St Michael not being recorded until 1786.

The present church was built in lancet style to designs of R.J.Withers in 1872-3. It consists of simple nave and chancel with cusped lancets in pairs, neatly done. It has an ashlar octagonal bell-turret, corbelled out, with punched quatrefoil openings and tiny lucarnes. In the south gabled porch is a reset plaque of 1591. There is a vestry on the north side. The interior was economically designed with fittings which included a bowl font and two-bay ashlar pulpit front modelled without extraneous ornament. A single-light stained glass window dates from 1956, by Celtic Studios. The church closed in 1999 and by 2003 was in private ownership, although the churchyard was still in use and in ecclesiastical ownership.

Sources include:
Dyfed Archaeological Trust, 2003, Early Medieval Ecclesiastical Sites Project, Pembrokeshire
T.Lloyd, J.Orbach & R.Scourfield, Buildings of Wales: Pembrokeshire (2004), p.494.
Report from an archaeological assessment of St Michaels Church, Eglwyswen, Crymych (West Wales Archaeology, 06/2004, including desk based assessment, building recording and watching brief).

D.K.Leighton & G.M. Edwards, RCAHMW, 11 June 2015