Obstructive sleep apnea (OSA) has recently been highlighted by an incident that a Shinkansen bullet train driver with OSA dozed off at the controls, and it had a great impact on society in Japan. Many studies have elucidated a relationship between OSA and its comorbidities, including hypertension, cardiovascular diseases and stroke. Snoring, which is the main symptom of OSA and has high prevalence, is a serious problem in that it disturbs not only snorers' sleep but also their bed partners' sleep. Previous epidemiological studies showed the relationship between subjectively measured snoring using questionnaires and cardiovascular disease, but in those studies snoring was considered as a surrogate marker of OSA. Although the clinical significance of snoring without OSA has not been emphasized to date, several studies have recently shown the association of snoring with excessive daytime sleepiness and blood pressure elevation independently of OSA. The clinical importance of snoring is desired to be clarified in the future.