Plethodon elongatus is a medium-sized, slender salamander. Adults are from snout to vent, and in total length. Limbs are relatively short; toes are short and slightly webbed. Dorsal coloration is dark brown or black. A reddish or reddish-brown straight-edged mid-dorsal stripe may extend from the head to the tip of the tail; the stripe may be less pronounced in older animals.
