Normal data for hemorrhagometry were established in 43 control persons, aged between 4 and 14 years. At room temperature the mean value for bleeding time was 4.61 min. (upper limit of normal 7.7 min.), the mean hemoglobin loss, which corresponds to the blood loss, was 4.34 mg (upper limit 14.74 mg), the mean value for maximal bleeding intensity was 21.4 mug hemoglobin/sec. (upper limit 48.8). When hemorrhagometry is performed at 17 degrees C (cold tolerance test) bleeding time is prolonged (mean 9.02 min., upper limit 14.3 min.), bleeding intensity increases (mean 32.4 mug Hb/sec., upper limit 81.3 mug/sec.), and hemoglobin loss rises (mean 11.07 mg, upper limit 31.36 mg). Bleeding time determinations according to IVY yield shorter values (mean 2.99 min., upper limit 4.5 min.) than those obtained by hemorrhagometry at room temperature. There was no positive correlation between hemorrhagometry parameters and age, sex, and number of thrombocytes, as long as thrombocyte counts above 100.000/mm3.