Introduction: In this study, changes that occur in various blood parameters as determined by the Sysmex XE-5000 analyser upon storage of blood samples for 72 h were investigated. Methods: Blood specimens (200) were processed through the SYSMEX XE-5000 haematology analyser within 4 h of collection. Each specimen was distributed into two aliquots and one stored at 4 °C and the other at room temperature (25 ± 1 °C). Both stored aliquots were retested after 24, 48 and 72 h. The mean, mean per cent change and mean absolute difference between the value at 4 h and each time point for all parameters were calculated. Results: Among CBC parameters tested, the white cell count, red cell count and haemoglobin levels were found to be stable for up to 72 h. The mean cell volume and haematocrit changed significantly following 24-h storage at room temperature. Reticulocytes were stable for 72 h under both storage conditions. Among the differential parameters, results of the monocyte count displayed significant change after 24-h storage at room temperature. Conclusion: The data presented suggest that clinically reliable results for some CBC parameters can be obtained from specimens that are stored at 4 °C for up to 72 h.