Epidemiological studies have demonstrated rates of incontinence and enuresis as high as 20% in school-age children. This cross-sectional study aimed to investigate the prevalence of lower urinary tract (LUT) symptoms in 739 children aged 6-12 years enrolled in three government schools with different socioeconomic levels in Minas Gerais, Brazil. Symptoms of LUT were evaluated using a modified version of the Dysfunction Voiding Scoring System in which the cutoff point considered as an indicator of LUT dysfunction is >6 for girls and >9 for boys. Children with a score indicative of symptoms received an educational booklet on the functioning of the LUT and were sent for clinical evaluation. LUT dysfunction symptoms were detected in 161 (21.8%) children. Symptoms were most frequent in girls (p < 0.001), children aged 6-8 (p < 0.028), and attended the school with the lowest social level (p < 0.001). Intestinal constipation was the most prevalent finding (30.7%), independent of LUT score. The most common urinary symptoms in children with an elevated score were diurnal urinary incontinence (30.7%), holding maneuvers (19.1%), and urinary urgency (13.7%). Stress factors were associated in 28.4% of children. Our findings suggest that LUT symptoms must be investigated carefully at routine pediatric visits.