Preservation of blood components for transfusion is a long-standing phenomenon. However, studies of cryopreservation of leukodepleted canine erythrocytes are quite limited and no studies are available with respect to morphological evaluation of erythrocytes during the cryopreservation process. The aim of this study was to determine morphological changes caused by cryopreservation, storage and leukocyte filtration. Healthy adult dogs meeting the criteria for blood transfusion were used in this study. Packed red blood cells (pRBCs) were obtained from each dog. The samples were divided into two groups. Leukocyte filtration was performed on one group of pRBCs. The other group received no filtration. The samples of each group were then allocated into three sub-groups according to storage period and subjected to glycerolization (40% w/v Glycerol) prior to cryopreservation except for day 0 group. Glycerolized samples were stored at -80 degrees C for four and six months. Blood smears were obtained from the samples of day 0 and those thawed and deglycerolized at the end of the storage period. The smears were morphologically evaluated by light microscopy, and Morphological Index (MI) was calculated. MI values of the non-leukodepleted (nLD) and leukodepleted groups (LD) increased from 0.083 and 0.119 to 0.238 and 0.273, respectively. In conclusion, leukocyte filtration did not have impact on the MI values of leukofiltrated and glycerolized pRBC samples but the cryopreservation and storage period did.