The association between snoring, nocturnal cough, and allergic symptoms in young children is not known. To measure the prevalence of habitual snoring and its association with nocturnal cough, asthma, and hay fever in preschool children. A cross-sectional study. Preschool children aged 2 to 5 years. The data were collected in a cross-sectional study. A total of 974 children were randomly selected from two areas of Lismore and Wagga Wagga in New South Wales, Australia. The prevalence of snoring was 10.5%, with no gender difference (p = 0.99) or trend association with age (p = 0.58). The association between snoring and nocturnal cough was highly significant (odds ratio OR, 3.68; 95% confidence interval CI, 2.41 to 5.63; p = 0.001). This association was significant in both the nonasthmatic and asthmatic groups when examined separately. Snoring was also significantly associated with asthma (OR, 2.03; 95% CI, 1.34 to 3.10; p = 0.001). In subjects without hay fever, the association between snoring and asthma was also highly significant (41.2% vs 24.8%; OR, 2.12; 95% CI, 1.34 to 3.37; p = 0.001). The prevalence of snoring in preschool children was 10.5% for both genders. Snoring was significantly associated with both nocturnal cough and asthma. Because snoring, asthma, and nocturnal cough may have a common etiology, it is possible that effective treatment of one symptom may lead to reductions in the presence or severity of the other symptoms.