The prevalence of nasal polyposis (NP) in France (2.11 per cent) and its epidemiology (detection, medical management, patients' characteristics, risk factors, associated diseases, etc.) were determined in a population-based, cross-sectional, case-control study of 10 033 adults carried out in 2002. The impact of this disease on daily living was also studied, by the analysis of potential sleep disorders (validated questionnaire) and quality of life (QOL, SF-36 questionnaire) of NP patients, in a comparison with a matched-control group of individuals without NP. A quarter of NP patients (24.6 per cent) reported a feeling of general discomfort due to their nasal condition, during the day as well as the night in most of these cases (61.2 per cent). Compared with controls, NP patients have a two-fold higher risk of suffering sleep disturbance (odds ratio [OR]: 2.25, 95 per cent confidence interval [95% CI] [1.54; 3.29]). Snoring was reported by 50.5 per cent of NP patients vs 35.7 per cent of controls (p < 0.001). All scores from the SF-36 questionnaire demonstrated a significant negative impact of NP on the different aspects of QOL. The current study underlines the negative impact of NP on QOL and sleep, two dimensions that are rarely considered in its pathology. In addition to the discomfort and lowered QOL experienced by patients with this disease, a significant increase in sleep disorders was shown, suggesting a risk of suffering further chronic diseases and complications.