Quercus obtusata is a tree up to 20 metres (66 feet) tall with a trunk sometimes more than 60 centimetres (24 inches) in diameter. The leaves are thick and leathery, up to 22 cm (8+3⁄4 in) long, widely egg-shaped with 3–9 pairs of shallow rounded lobes or undulations.[4][5][6]
Resembles Q. potosina, which has smaller leaves (3–10 x 2–6 cm); also resembles Q. rugosa, this one has a convex leaf strongly coriaceous, a revolute margin, the epidermis bullate; at least, one can differentiate Q. obtusata from Q. laeta, which has foliar underside glaucous, without masses of glandular secretions, none or rare glandular trichomes, a leaf more oblong than oboval with a margin sometimes entire.