Acutiserolis poorei sp. nov., is described from the Amundsen and Bellingshausen Seas, Southern Ocean. Comparison with the type material of the most similar species, Acutiserolis spinosa (Kussakin, 1967) revealed that A. poorei may be distinguished from A. spinosa by broader eyes, less acute and slightly shorter coxal plates and the small tubercles that are irregularly scattered on the dorsal surface. Additionally, no suture divides the fifth coxal plate and the head has a prominent mediocaudal spine reaching to the middle of the third pereonite; the appendix masculina is considerably shorter than that of A. spinosa, while the pleotelson of A. poorei is covered with some small tubercles and the mediocaudal tip is slightly more prominent than that of A. spinosa.