Recent studies have strengthened the concept that bronchial asthma and allergic rhinitis are manifestations of an inflammatory process within a continuous airway. This study was performed to compare clinical findings in asthma with or without rhinitis in Japan. Nasal symptoms were present in 99.6% of asthma patients. The prevalence of allergic rhinitis in patients with asthma was 52.4%. Bronchial asthma attacks in one third of patients with rhinitis were coincident with worsening of nasal symptoms. In adults (> 16 years of age), rhinitis frequently preceded asthma, whereas asthma preceded rhinitis in children (< 16 years of age). The frequency of rhinitis in asthma decreases with increasing age. This study demonstrated a clear link between upper and lower airway disorders in Japan.