Two or three leaves grow from the top of a Polystachya ottoniana pseudobulb. The strap-shaped leaves curve outwards opposite each other. The blade turns up slightly from the sunken midrib in the nearly flat leaves. Leaf tips are rounded to obtusely pointed. Leaves become from 2 cm to 13 cm long and 4mm to 8 mm wide. Leaves may be shed by the plants in the cold(er) rest season.

The fibrous remains of old bulb sheaths are often visible around the vertically flattened pseudobulbs that form long strings and eventually dense cushions. The plants are perched on tree trunks or branches, sometimes on rocks. Old bulbs often turn yellowish cream (Liltved and Johnson, 2012; Germishuizen and Fabian, 1982).