Few-flowered spike-rush is a graminoid, 1-4dm tall, with spikelets that are 3-8mm x 1.5-4mm, with 3-10 floral scales per spikelet. Its 3-6 perianth bristles are often unequal, rudimentary to equaling tubercle, stout to slender, and spinules are dense to apparently absent. Its achenes are stramineous to medium brown or gray-brown, equilaterally trigonous to compressed-trigonous, rarely some biconvex, obpyriform, with a variable beak. Tubercles are rarely absent. Distal leaf sheaths are stramineous to brown or reddish proximally, green to stramineous or brown distally, mebranous to papery, apex often reddish, and are subtuncate to acute. Its scales are persistent or fugaceous, thinly membranous, and not fibrous. Resting buds are often present on rhizomes or among culm bases and are broadly to narrowly ovoid. Proximal scale has a flower and is seldom empty.
It superficially resembles the common E acicularis, but it has shorter stems (1-4dm vs greater than 4dm) and fewer than 10 flowers per spikelet.