The pulmonary functions were measured during resuscitation of eight critically ill newborns by the "Pulmonary Evaluation and Diagnostic System" (PEDS UNIT-M.A.S. Inc.) The asphyxiated infants (Apgar score 0-3; PH 6, 9) required more aggressive ventilator support than "traditional" cases. The danger of the pulmonary injuries was larger in this period. In spite of this, there were no signs of air leaks syndrome and the oxygenation was improved in every case. Worsening or improving the pulmonary mechanics it is possible to change the ventilator settings immediately. This method seems to be advisable to introduce in the everyday routine to prevent iatrogenic pulmonary complications in such critical situation--the reanimation.