In 310 individuals (165 men and 145 women) significant pathological processes were exluded by reference to the patient's history, by physical investigation and by detailed laboratory tests (clinical chemistry, hematological cytology and most important coagulation analyses). Hematological laboratory values were then evaluated for age and sex differences, and in women according to menstruation versus post-menopause an oral contraception. Only the well known sex-specific differences in hematocrit values, hemoglobin and red cell counts were statistically highly significant (Z > 10). All other hematological values were pooled after exclusion of methodological errors. According to the non-symmetrical distribution of hematological laboratory values, percentiles were calculated. The 2.5 to 97.5 percentiles thus established now serve as "normal hematological reference values" for our laboratory.