OBJECTIVE: To determine the prevalence and impact of pediatric abdominal pain (AP). STUDY DESIGN: Prospective cohort study (12/2005-06/2006), with gastrointestinal and other symptoms assessed weekly. Anxiety, depression, functional disability, quality of life, somatization, coping, school absenteeism and medical care were assessed in 237 students in the third through eighth grades (11.8 years; 134 girls) from 2 public schools weekly. Complete data were obtained on 4606 of 5175 (89%) possible questionnaires. RESULTS: Seventy-two percent of children reported >1 somatic symptom weekly, and 45% of children reported >1 gastrointestinal symptom weekly. The weekly prevalence of AP was 38%, and 90% of children reported AP at least once. AP persisted >4 consecutive weeks in 52% of children and was associated with higher anxiety (P < .001) and depression (P < .001) scores and worse quality of life (P < .001). Twenty-three percent of children missed school for AP (average, 2.3 days), and 10% of parents of those children missed work (average, 1.9 days). Presence of AP (P < .001) was independently associated with school absences. Four children (2%) sought medical attention. CONCLUSIONS: AP is common in school-age children and is associated with worse quality of life, psychological co-morbidities, school absenteeism, and parental work absences.