Melicope peninsularis is a tree that typically grows to a height of and has a slender trunk. The leaves are arranged in oppositepairs and trifoliate on a petiole long. The leaflets are sessile, elliptical, long and wide. The flowers are arranged in panicles about long in leaf axils and are bisexual and the sepals about long and fused at the base, the petals white, long and there are four stamens. Flowering has been recorded in February and the fruitconsists of four follicles long and fused at the base.