The genus Kolga has been revised. Kolga nana (Théel, 1879) is re-established and a new species, Kolga kamchatica sp. nov., is described. The new species was found in the Kurile–Kamchatka Trench at 6225–6236 m water depth. The three species of Kolga, K. hyalina, K. nana and K. kamchatica, differ mainly in morphology of tube feet ossicles. For the first time, swimming activity is reported in K. nana.