Plumeria obtusa can grow as either a small shrub or tree ranging in height from 0.9-6.1 meters with widely spaced thick succulent branches that are often covered with “knobby” protuberances. The leaves are found in clusters near the tips of the branches. They are large (6-22 cm long and 2-7 cm wide) and have a characteristic oblong shape and the tip of the leaf is obtuse (rounded) rather than pointed as it is in other species. The leaves are dark and leathery and tend to be shiny on the upper surface with conspicuous parallel secondary veins that run from the midvein to the margins of the leaves.
The flowers of this species are borne in inflorescences (clusters) that form at the ends of the branches on a long thick stalk. Each inflorescence contains many white flowers with a small yellow center creating splashes of color throughout the tree. The well-known and characteristic Plumeria flowers contain five petals that are fused at the base in a short funnel-shaped tube, which gradually widens as the lobes of the petals are spread out.