A microtechnique of evaluation for the haemoglobins A2 and F is presented, in which the final measurement is made more sensitive by evaluation of peroxidatic activity. Haemoglobin A2 is previously separated by chromatography on a very small column of DEAE cellulose and haemoglobin F is obtained through a microtechnique of alkaline precipitation. The sensitivity of this evaluation is increased by a factor of 20.25 microliter of hemolyzate are enough for a determination. Results obtained are in accordance with those given by the classical methods.