Reference values for hematologic parameters are determined using data from patient populations of a whole year. As a consequence, the authors are not dependent on a limited selected population and can determine reference values for all age and sex groups. It turns out that from the possible compilation technics the gamma distribution gives the best fit. If the results are compared with values stated in the literature, it is remarkable that the total number of leukocytes for men older than 50 years is higher than for women; both the absolute and relative amount of monocytes and eosinophilic granulocytes are higher for men than for women. The platelets are lower for men than for women from the age of 15 years on.