Stenogyne kealiae is a trailing or scandent stiff vine. The stems are characteristically weakly 4-angled and maintain a glabrous texture. The leaves are arranged oppositely and feature broadly lanceolate to elliptic-lanceolate blades measuring 8–15 cm in length and 2.5–4.5 cm in width. These blades have an acuminate apex and vary at the base between acute, rounded, truncate, or weakly subcordate forms. Both surfaces of the leaves are glabrous, and the blades themselves are thin to moderately coriaceous with weakly revolute and subentire to weakly serrate or crenate-serrate margins, especially pronounced in the upper half. The petioles extend 12–35 mm and are also glabrous. The flowers grow 3–5 per verticillaster (inflorescence that resembles a whorl but consists of two crowded cymes on either side of the stem) in the axils, with pedicels that are 4–5 mm long and display a moderate to sparse puberulence. The calyx is narrowly campanulate, measures 9–12 mm at anthesis, expands as the fruit develops, and features sparsely puberulent or subglabrous surfaces. Corolla lobes are deep pinkish purple with a whitish base, strigose externally, and glandular-pubescent inside, forming a narrow funnelform tube about 15–17 mm long. The stamens are exserted or included within the corolla, with pubescent filaments. The fruits are dark purple nutlets when mature, about 7–8 mm long, drupaceous, and black at maturity with slightly winged margins that are obliquely attached at the base and enclosed within the calyx. The seeds lack an endosperm or are scanty and oily. The habitat is primarily wet forest within Kōke’e State Park in the Waimea District of Kaua’i, spanning from Awa’awapuhi to Kalalau valleys between 1,090-1,250 meters.