The cycle of alternating distribution of nasal airflow was investigated in 15 adults. Information about cyclic activity was obtained from the areas of condensation formed by nasal expiration on the surface of a Gertner-Podoshin plate. Consecutive measurements of these areas were made at 15 minute intervals during a 6-8 h period. Five control subjects demonstrated a nasal cyclic activity which was absent in 5 patients 1-3 years post laryngectomy. Two patients with preoperative cycles showed none 3 weeks after laryngectomy. Three patients with temporary surgical diversion of supraglottic airflow showed cessation of the cycle, which resumed after restoration of the natural airway; one of these patients had undergone hemilaryngectomy with section of both superior laryngeal nerves. These results demonstrate cessation of the cycle following chronic absence of supraglottic airflow, temporary cessation during acute absence, and independence of the cycle from superior laryngeal innervation.