"Liliensternus" was approximately long, and may have weighed about . Other estimates suggest that "Liliensternus" was at best long and weighed at most. The remains of two specimens of "Liliensternus" together form a syntype series with inventory number MB.R.2175, and consist of the partial and fragmentary skeletons of at least two individuals, containing elements of the skull, the lower jaws, the vertebrae and the appendicular skeleton. The tibia (409 mm) is shorter than the femur (440 mm) in both "Dilophosaurus" and "Liliensternus", unlike those of coelophysid taxa, such as "Coelophysis". Paul (1988) noted that based on its appearance, "Liliensternus" could be considered to be an intermediate between "Coelophysis" and "Dilophosaurus". Although the skull is not well known, many reconstructions have "Liliensternus" with a crest similar to that observed in "Dilophosaurus". Its ilium (hip bone) is unusually short, as is the case with "Dilophosaurus". "Liliensternus" has five fingers, much like its contemporaries, but its fourth and fifth digits are smaller than the rest, a possible transitional stage between the five fingered theropods of the Triassic and the three fingered theropods of the Jurassic.