This study was carried out on 80 healthy, four-year-old Holstein dairy cows bred in the Bursa region. Twenty of them were in the dry period and the rest were in the lactation period. Days 48-51, 147-161 and 180+ of the lactation period were considered the first, second and third stages, respectively. Blood samples were analysed for packed cell volume, red blood cell count, haemoglobin values, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and white blood cell count. There was a statistically significant effect of dry period and lactation on blood parameters except MCV and white blood cell count.