The allergic rhinitis (AR) is an important risk factor for the development of asthma. In significant number of patients with AR, the non-specific bronchial hyperresponsiveness (BHR) could be demonstrated. It has been anticipated that these patients were at the greater risk for asthma. This study was aimed to determine the frequency and intensity of BHR in patients with seasonal AR (SAR) due to Wall pellitory allergy. The patients who were sensitized solely to Parietaria officinalis (Wall pellitory) pollen allergen were recruited in the study, namely patients with SAR (n = 26), SAR with seasonal asthma (n = 23) as well as healthy volunteers (n = 10). In all subjects the clinical check-up, spirometry and bronchial challenge test with metacholine were performed before, during the peak, and after the peak of pollination of pellitory. Comparing to initial findings (23%), in patients with SAR the prevalence of BHR significantly increased during the peak of pollination (50%, p = 0.0039), and remained increased thereafter (43%, p = 0.0319). In patients with SAR and asthma prevalence and intensity of BHR was even higher with the similar seasonal variations. Comparing to initial findings (83%), the prevalence of BHR significantly increased during the peak of season (100%, p = 0.0001), and remained increased thereafter (87%, p = 0.061). In both groups of patients the intensity of BHR (median PC20) increased as well: 4.8, 2.05, and 2.45 mg/mL in patients with SAR, and 0.35, 0.16, and 0.20 mg/mL in patients with SAR and asthma. In healthy volunteers no significant BHR was observed. The results of the present study confirm significant prevalence of BHR in patients with SAR due to pellitory allergy. It is important to determine BHR in patients with SAR and without asthma because the appropriate pharmacotherapeutic and preventive measures (anti-inflammatory medication and specific immunotherapy) could prevent the development of asthma in these patients.