Recently a nose plaster (NP, Breathe-Right) has been increasingly used in the treatment of obstructive sleep apnoea (OSA) and snoring. Hence, we examined the use of the NP as a treatment of both OSA and snoring without OSA. The NP has a elastic spine that increases the diameter of the nostril and is thought to reduce the degree of OSA and snoring. According to the polysomnographic data two groups were differentiated: Group A (30 patients with OSA, apnoea index > 10/h, 26 men) and Group B (20 snorers, without OSA, 13 men). After the diagnostic polysomnography the efficacy of the NP was measured with a cardiorespiratory polygraph on the 2 following nights. In the group A the polygraphic data (apnoea index, time of apneas, desaturation index, time of desaturations, mean and nadir SaO2) were studied; in group B the snoring index (snoring events/hour) was measured. A questionnaire scored quality of sleeping, daytime condition and the quality of nose breathing. In neither group were the recorded polygraphic findings different with the NP although with the NP an improved nose breathing was scored in both groups. In group A 90% of the patients scored the daytime sleepiness unchanged and 10 of 30 patients described an improved quality of sleep. In group B there was no change in the frequency of snoring events with the NP. Neither the degree of OSA nor of snoring without OSA were changed by the NP, which can therefore not be considered a treatment of these conditions. However, the majority of the study population were impressed by the symptomatic improvement in nose breathing.