The ultimate objective of our epidemiological research is to complete a longitudinal population-based study to document the prevalence and impact of acute, recurrent, and chronic pain in children and adolescents. As the first phase of our epidemiological research, we developed a comprehensive screening instrument for identifying children with acute, recurrent, and chronic pain, the Pain Experience Interview. We designed this interview to provide information about the lifetime and point prevalence of various pains, and also to provide information about the intensity, affect, duration, and frequency of children's pain. The primary objective of this study was to validate the Pain Experience Interview using the discriminant validation procedure of group differences. The secondary objectives of our study were to obtain descriptive data on children's acute, recurrent, and chronic pain experiences and to conduct exploratory analyses on age- and gender-related differences in children's pain experiences. We interviewed 187 children from five different health groups (arthritis, cancer, enuresis, recurrent headaches, and healthy) to provide distinct subsets of children with respect to their acute, recurrent, and chronic pain experience, and from four different age groups (5-7, 8-10, 11-13, and 14-16 years) to provide distinct subgroups with respect to children's developmental level. To test the interview we determined a priori several study predictions about children's pain experiences. These included four predictions about the common response patterns that we would expect to observe for all children based on our understanding of acute pain caused by trauma/disease, and six predictions about the distinct response patterns that we would expect to observe based on the known differences among children in their experiences of headache, acute treatment-related pain, recurrent pain, and chronic pain. All study predictions were confirmed, demonstrating that the Pain Experience Interview is a valid screening instrument for differentiating children with different types of pain problems. The interview can provide estimates for the lifetime and point prevalence of various pains in children, and data on the intensity, affect, duration, and frequency of their pain experiences.