A research on the effect of water temperature change on erythrocyte profile was conducted on Prussian carp (Carassius gibelio) from the Bardača area (BiH). The study included 38 individuals which were divided into two aquaria, adapted to experimental conditions and then subjected to different temperature regime. The control group had constant water temperature of 10ºC, while for treated fish water temperature was gradually increased to 20ºC for three days. Conducted analysis of erythrocyte profile, which includes erythrocyte count, hemoglobin concentration, packed cell volume, MCV, MCH and MCHC showed that individuals exposed to temperature increase had significantly higher values of erythrocyte count and packed cell volume, while control individuals had higher values of MCH and MCHC.