Background: Wheezing is one of the most frequent causes of visit to emergency rooms among children. However, data on wheezing burden are mostly provided at healthcare setting, and particularly only for infants. Aims: We sought to estimate the prevalence of wheezing in children under 4 years and to assess potential risk factors in the community. Design: This was a cross-sectional analysis of a population-based cohort study. Methods: The sample comprised children aged <4 years living in Salvador, Brazil. Data were collected via home visits when the parents/guardians were interviewed. Data were recorded on standardized forms. Results: Of 1534 children, mean age was 21 14 months (minimum 3 days; maximum 47 months; 6% <2 months); 780 (51%) were males and 501 [33%; 95% confidence interval (95% CI): 30–35%]reported wheezing in the last 12 months. Among wheezers, 321 (64%) had occasional wheezing. Overall, 180 (12%; 95% CI: 10–14%) had recurrent wheezing and 157 (10%; 95% CI: 9–12%) had asthma. For children in the first, second, third and fourth year of life wheezing was reported in 23, 41, 34 and 37%, respectively. Mother atopic-related disease was independently associated with recurrent wheezing (AdjPR[95% CI]: 1.54 [1.12–2.11]) and asthma (AdjPR[95% CI]: 1.54 [1.10–2.16]). Smoker at home (AdjPR[95% CI]: 1.34 [1.07–1.67]) and low birth weight (AdjPR[95%CI]: 1.38 [1.05–1.81]) were independently associated with occasional wheezing. Conclusions: One-third of under 4 years reported wheezing; history of mother’s atopic-related disease was an independent risk factor for recurrent wheezing and asthma; smoker at home and low birth weight were independent risk factors for occasional wheezing.