Ampelocissus ascendiflora is a herbaceous climber with a longitudinally ridged stem, up to 3 mm across, often white tomentose when young, turning brown when older. The tendrils are simple and each has a prominent, ovate bract, similar to the stipules. The leaf is white-tomentose when young, turning brown below and sparsely hairy above when older. The leaf blade is ovate, 4.5–18.0 × 5.5–14 cm, and petiole 4.5–16.0 cm long. The inflorescence is a panicle of spikes, 13–21 cm long. The flower has red petals and a yellow disc. The berry is about 8 mm across with 2 seeds about 7 × 6 mm. It is only known from the Malay Peninsula and Singapore.