Cyrtandra oxybapha is a shrub growing 2–3 meters tall with many-branched, rounded to angular stems that are pubescent with multicellular hairs or can be glabrate. Its leaves are simple and opposite, located on the upper 3–4 nodes, with each pair of leaves being unequal and slightly asymmetrical. The leaves are chartaceous, suborbicular to very broadly elliptic, measuring approximately 12–18 cm in length and 8–9 cm in width, featuring an acuminate apex and a truncate to broadly cuneate base. The upper leaf surfaces are moderately hirtellous, the lower surfaces are densely velvety villous, and the edges are coarsely and irregularly serrate–dentate. The petioles are 4–6.5 cm long, densely covered in brown villous hairs, and may clasp the stem at the base. The flowers are 1–2 per cyme, emerging from the leaf axils, with a dense covering of villous hairs. The peduncles and pedicels are stout and elongate during fruiting, with foliaceous bracts that are very broadly elliptic. The calyx is nearly actinomorphic, pale green, and broadly campanulate, splitting about half its length, with lobes that are broadly elliptic and densely villous. The corolla is presumed white and bilabiate, with a subcylindrical tube flaring below the mouth and rhombic orbicular lobes. It has five stamens, with the upper two being fertile and the others staminodial. The fruit is a fleshy or firm berry, white in color, ovoid, approximately 1.8 cm long, and often tipped with a persistent stylar beak, surrounded by the persistent, spreading calyx. The seeds are numerous, ellipsoid, and typically smaller than 1 mm long, with a reticulate surface. It is known only from one site in wet forest habitats around 1,130 meters.