Cycas chamaoensis is named after the only known habitat of this species, on and near Khao Chamao mountain in Khao Chamao District, Thailand. Stems are arborescent, either erect or decumbent. Leaves numerous, exceeding 60 per crown, 1.2-2.5 meters in length, ending in terminal spine. Petiole 30–60 cm, glabrous and partially spiny. Leaflets in 85-155 pairs, and lanceolate, glabrous and angled forward at 60-70 degrees.