The Branchiopoda, Maxillopoda and Ostracoda fauna of 59 high mountain lakes of Kackar mountains was investigated for the first time. During the study, six expeditions were carried out in the Summers of 2005-2007. All lakes are located at altitudes between 2530 and 3370 m except Uzungol (1100 m). Beside the biological samplings, major environmental variables of the lakes were measured. A total of 21 Branchiopoda, 9 Maxillopoda and 3 Ostracod taxa were identified. All the taxa identified are new records for their. localities except C. ponticus. The investigated ecosystems support a high micro-crustacean diversity that must be adequately preserved due to the increasing direct and indirect impacts on high mountain lakes.