The goal of this study was to compare the effectiveness of three treatments aiming to reduce nasal airflow resistance (NR): an external nasal strip device (Respir+), an internal nasal mechanical dilator (Nozovent), and a topical decongestant (Pernazène). NR was estimated by active posterior rhinometry at both a 0.5 L/s flow (NRf) and a 1 cm H2O pressure (NRp), under four conditions: in the basal state, with Respir+, with Nozovent, and after treatment with Pernazène. The efficacy of each treatment was assessed by the percentage changes in NRF and NRP (%NRF and %NRP, respectively). The study was performed in 15 healthy subjects. The efficacy of the treatments was significantly different, depending on whether it was evaluated by NRF or by NRP (p<0.02), with %NRF and %NRP values, respectively, equal to the following: 88±20% and 91±14% with Respir+, 58±17% and 70±13% with Nozovent, and 55±29% and 69±22% with Pernazene. NRF remained unchanged with Respir+, whereas it significantly decreased with Nozovent and Pernazène (p<0.0001). No significant difference was observed between the effects of the two latter treatments. These results demonstrate that Nozovent, which involves no risk of side effects or drug interactions, is an effective treatment to improve nasal breathing. Nozovent might therefore be recommended as an alternative to topical decongestants, for certain subjects presenting with nasal obstruction.