Eight free-range koalas (Phascolarctos cinereus) were captured on Kangaroo Island (South Australia) and later transported to the Adelaide Zoological Gardens. Blood samples were collected at the time of capture and at 6 hr, 24 hr and 7 days later. Routine hematological analyses were performed and plasma cortisol levels determined. Significant differences were observed between sampling times for erythrocyte numbers, hemoglobin concentrations, packed cell volumes, mean cell volumes, mean cell hemoglobin concentrations, numbers of leukocytes, neutrophils, lymphocytes and lymphocyte:neutrophil ratio (P < 0.05). No significant differences were detected between sampling periods in the numbers of monocytes (P = 0.707), eosinophils (P = 0.174) or plasma cortisol levels (P = 0.192).