Hb concentration, PCV, erythrocyte and leucocyte counts in the peripheral blood, MCV, MCH and MCHC in a population sample of 1462 women in ages between 38 and 60 years are presented. In addition, a description is given of thrombocyte counts in 38-year-old women. Significant differences with age were found for Hb concentration and PCV and for leucocyte counts. High correlations were found between Hb and PCV in the various age groups studied, while lower correlations were found between erythrocyte counts on one hand and Hb or PCV on the other. There was an overrepresentation of smokers among women with high Hb values and among those with high leucocyte counts. The higher leucocyte counts in the youngest age groups could be explained by the larger number of smokers in these ages. Thrombocyte counts were lower in smoking than in non-smoking women.