Melicope paniculata is a small tree with new growth that is sparsely minutely puberulent, becoming glabrate with maturity. The young branches are reddish brown. The leaves are simple and arranged oppositely. The blades are elliptic or broadly elliptic, measuring 8–20 cm long and 5–10 cm wide. The surfaces are glabrous except for the midrib on the lower surface, which is sparsely appressed puberulent. The blades are thin and coriaceous, with strongly revolute and entire margins. The primary lateral veins number 10–18 pairs and are connected by a deeply arched vein 5–10 mm from the margin. The venation is pinnate, with lateral veins connected by an arched submarginal vein, and the higher-order venation forming a reticulate pattern. The petioles are 20–60 mm long, and stipules are absent. The flowers are arranged in elongate, cymose panicles, ranging from 11–50 per inflorescence and reaching up to 21 cm long. The peduncles are 70–90 mm long, and pedicels measure 2–5 mm long. Bracteoles are subulate and approximately 1 mm long. Bracts are small and opposite. Flowers can be bisexual (perfect) or functionally unisexual, with the plants being monoecious when unisexual flowers are present. The calyx consists of four sepals; in pistillate flowers, the sepals are ovate, approximately 2.7 mm long and 2.1 mm wide, glabrous, and imbricate. The corolla has four petals; in pistillate flowers, the petals are narrowly ovate, around 6 mm long and 3 mm wide, with a valvate arrangement. There are eight stamens, which are rudimentary in pistillate flowers. The ovary is superior in pistillate flowers, with four cells and four lobes. The carpels are connate, slightly distinct at the apex, to almost entirely distinct. The style is filiform, about 2.3 mm long, and terminates in four short stigmatic branches. The ovules are two per cell, hemitropous, with one ascending. The immature fruit is a cuboid capsule measuring 8–9 mm in length and width. The endocarp and exocarp are glabrous. The carpels dehisce along the upper suture. It is found in wet forests, sometimes near rivers and swamps between 580–875 meters.