A new species of Tenuidraconema Decraemer, 1989 is described from a cold-water coral degradation zone in the Porcupine Seabight (NE Atlantic). Tenuidraconema microsperma sp. n. is distinguished from all other species of Tenuidraconema by the combination of 10 CAT located posterior to the amphidial fovea, SlAT alternately long and short, male amphidial fovea composed of an inner and an outer loop, with ventral arm of inner loop as long as high, external labial sensilla papilliform, compact, jagged sperm cells with large, refractive inclusions, the shape of the gubernaculum and the number of tail rings. Additional descriptive data are provided for T. koreense Rho & Kim, 2004, from specimens found in the Porcupine Seabight. Additionally, the fourth-stage juvenile is described for the first time, the species diagnosis is emended, and the biogeography in the North Atlantic is discussed. The diagnosis of Tenuidraconema is emended, and a dichotomic identification key to the five included species is provided.