Background: The aim of the present study was to explore the relationship between excessive daytime sleepiness (EDS), Peak Nasal Inspiratory Flow (PNIF), and patient reported symptoms from the nose. Methology: Six hundred and fifty one consecutive patients referred to a hospital on suspicion of sleep related breathing disorder (SRBD) were included in the study. Daytime sleepiness was assessed by Epworth Sleepiness Scale (EpSS). Nasal airflow was measured with Peak Nasal Inspiratory Flow (PNIF). Symptoms of sino-nasal dysfunction and diseases were graded on Visual Analogue Scales (VAS). Results: EpSS score was not correlated with nasal flow as measured by PNIF or nasal obstruction-VAS scores. There were significant associations between daytime sleepiness and patient-reported VAS-scores on nasal discharge, headache, coughing, general health and to some extent sneezing when age, gender, BMI and reported co-morbidity levels were adjusted for. Conclusion: A clinical implication of this is that patients with EDS may be evaluated and treated for sino-nasal disease, while medical and surgical measures to open the nose per se may not be effective therapeutic options. A scientific implication is that the relationship between SRBD and sino-nasal disease should be further investigated.