The southern arm and its segment of encircling ring are gone entirely, broken off at some point before 1837, when the Ordnance Survey noted a cross with one arm missing exhibiting a very rude representation of the crucifixion. A short tenon projects from the top of the cross-head, suggesting it once supported a capstone, possibly church-shaped, that has since disappeared. The whole thing is 2.5 metres tall, cut from grey granite, and sits on Kilgobbin Lane, downslope from the old ecclesiastical complex, thirty metres northwest of the church and graveyard.

The cross was reportedly dug up from Kilgobbin graveyard in the early 1800s and re-erected in its current position, which may explain something of its oddly roadside character. The carving on both faces of the cross-head is what gives it genuine scholarly interest. The east face carries a Crucifixion in low relief, Christ robed to the ankles with arms outstretched. The west face shows a second figure of Christ, also robed but with noticeably shortened, stubby arms, which the archaeologist Peter Harbison interpreted as a possible depiction of the Risen Christ or Christ in Glory, drawing a comparison with the pectoral cross held in the Dumbarton Oaks collection. Harbison grouped Kilgobbin with a later set of Irish high crosses, including those at Cashel, Monaincha, and Roscrea, distinguished by their use of the long robe rather than the perizonium, the loin-cloth seen on earlier Crucifixion carvings. The west face figure has also been compared to the east face of the high cross at Moone, Co. Kildare. The shaft itself is plain on its broad faces, decorated only with a roll moulding along its edges, and tapers slightly toward the bottom where it slots into a morticed base boulder.

The cross stands on the south side of Kilgobbin Lane, adjacent to a small open green, in what is now the leafy fringes of south County Dublin between Sandyford and Stepaside. The graveyard and ruined church are a short distance uphill. The base stone is large and irregular, and the bullaun on its upper surface is on the southwest side; it is easy to miss if you approach from the wrong angle. The granite is weathered and the carvings are in low relief, so the figures read more clearly in raking morning or evening light than in flat midday conditions. The missing southern arm gives the cross an asymmetric silhouette that takes a moment to register as absence rather than design.