In nine distressed newborn infants, mean aortic blood pressure and motor activity were recorded continuously during the first two or three days of life. Six of the infants had been asphyxiated at birth, the remainder having idiopathic respiratory distress only. The results showed that mean arterial blood pressure varies synchronously with motor activity, reaching maximum values much higher than previously suspected: about 90 or 100 mmHg were recorded in several infants. In three cases focal and/or generalized epileptic seizures occurred during the recording. It was found that in these circumstances too blood pressure increases dramatically, even if the motor component of the seizure is insignificant.