The spiny-tailed monitor, a medium-sized monitor lizard, can attain a total length of up to 70 cm. The tail is about 1,3-2,3 times longer than head and body. The upper side is a rich, dark brown and painted with bright yellowish to cream spots, which often enclose a few dark scales. Its tail is round in section and features very spinose scales. There are 70-115 scales around the middle of the body. The spiny-tailed monitor is distinguished from the similar-looking species V. baritji and V. primordius by the presence of pale longitudinal stripes on the neck.