Asilisaurus was a lightly built animal with a fairly long neck (by early archosaur standards), a short snout tipped with a beak, and slender limbs. It probably walked on all four legs based on the length of its limbs. Asilisaurus specimens have been estimated to measure from 1 to 3 m long and 0.5 to 1 m high at the hip, and may have weighed 10 to 30 kg.

The ~3 meter upper length estimate is based on NHMUK R16303, an incomplete silesaurid femur found in the Manda Beds. This femur had an estimated length of 29.6-39.6 cm (11.7-15.6 in),