Melicope zahlbruckneri is a medium-sized tree reaching 10–12 m in height. New growth is yellowish-brown and puberulent, gradually becoming glabrate with maturity. The leaves are simple and opposite. Blades are oblong-elliptic, oblong–obovate, or occasionally suborbicular, measuring 6–24 cm long and 4–12.5 cm wide. Upper surfaces are glabrous, while lower surfaces are puberulent and gradually become glabrate. Blades are chartaceous to moderately coriaceous, with entire margins. Primary lateral veins usually form 8–10 prominent pairs, connected by an arched submarginal vein about 3–9 mm from the margin, with a pinnate venation pattern and higher-order venation forming a reticulate pattern. Petioles are 20–45 mm long. Stipules are absent. The flowers occur in slender, sparsely puberulent, axillary cymes of 2–5 flowers, with peduncles that are somewhat flattened and measure 15–20 mm long. Pedicels are about 4 mm long with small, opposite bracts. The calyx has 4 imbricate sepals; in pistillate flowers, sepals are deltate and approximately 1.5 mm long and glabrate, while staminate flowers have deltate–ovate sepals about 3.5 mm long and glabrate. The corolla consists of 4 valvate petals; pistillate flower petals are deltate and approximately 3 mm long, while staminate flower petals are deltate and around 6 mm long, both glabrate. There are 8 stamens arranged in 2 whorls, and they are reduced in pistillate flowers but always present. Staminate flowers have a glabrous nectary disk. The ovary is superior, 4-celled, and 4-lobed in pistillate flowers, with connate carpels but slightly distinct at the apex. There is 1 style, about 1 mm long, terminating in 4 short stigmatic branches. The capsules (fruit) are subcuboid, measuring 12–14 mm long and up to 30 mm wide. Carpels are nearly completely connate or connate about ⅔ their length and often recurved, dehiscing along the upper suture. The seeds are 1–2 per carpel, glossy black when ripe, 7–8 mm long, crustaceous, ovoid, and sometimes angled due to compression. Seeds contain a straight embryo in fleshy endosperm, with a short radicle and ovate, compressed cotyledons. The putamen is brown and warty. It occurs in mesic forests around 1,220 meters.