By means of active anterior rhinorheomanometry we searched for nasal cycles in children of 3-10 years of age. We measured the nasal air flow every 15 minutes for a period of 2 hours on both sides in relation to a pressure of 1 mbar. In the group of the 7-10 year old children we found nasal cycles in 79 per cent according to Hasegawa's and Kern's definition. In contrast to other authors nasal cycles were also ascertained in 50 per cent of the 3-6 year old children: Computing the correlation coefficient between the difference of one measurement from the right and left mean nasal air flow, we could demonstrate that the nasal cycle was actually subject to a regulatory mechanism. In contrast "solidary movements" showed no regulation in our challenge-controlled measurements.