P. lilfordi is named in honour of Thomas Powys, 4th Baron Lilford, a British ornithologist who studied the fauna of the Balearics.

[5] Lilford's wall lizard grows to a maximum snout-to-vent length (SVL) of 8 cm (3 in), but adults are usually a little smaller than this.

It is a robust streamlined lizard with a short head and rounded body with smooth, unkeeled scales.

[2] It is a mainly ground-dwelling species and largely inhabits rocky areas and scrubland, although it is found in woodland on Cabrera.

[2][4] Breeding takes place in the summer, and females may lay up to three clutches of one to four eggs with an average mass of 0.63 g, large for a lizard of this size.

This extirpation may have been caused by the proliferation of cats and by other introduced predators, possibly the false smooth snake (Macroprotodon cucullatus) and the weasel (Mustela nivalis).

Its total area of occupancy on all the small islands on which it is now present is less than 500 km2 (193.1 sq mi); so the IUCN lists it as being "Endangered".