Helicodesmus subcylindricus sp.n. is described from forest litter in southern Vietnam. It differs from the sole, and type, species H. anichkini Golovatch, Geoffroy et VandenSpiegel, 2014, also from southern Vietnam, by the subcylindrical body virtually devoid of paraterga, the shorter metatergal setae, the possible absence of ozopores from segment 18 and, above all, the less elaborate, albeit still fairly complex gonopods.