Ptilidium ciliare grows in loose, reddish-brown to yellow-green tufts, with individual shoots up to 3 mm wide. Its stems are pinnate or bipinnate, with short stubby branching clusters of dense with overlapping leaves covering its stem. The leaves are up to 2.8 mm wide and 2.3 mm long, and the leaves are finely serrated or ciliated, the margins extended as fringe-like rows of thin teeth. The teeth make it difficult to see that the leaves are bilobed. Sexual reproductive structures are very rarely observed on this species.