Our knowledge of the prevalence and sources of pain within hospital is limited. The present study is an epidemiological investigation of pain in a pediatric hospital. All children who were inpatients in a tertiary care hospital (excluding Neonatal ICU and psychiatry patients) and one parent per child were potential subjects. Interviews were conducted on three weekdays. Parent interviews were used for children less than 5 years of age (n = 102); child interviews were used for children age 5 years and older (n = 98). Subjects reported the intensity and source of the worst, usual and current pain during the past 24 h, and help received for pain. Medical and demographic variables and analgesics prescribed and administered were obtained from the medical record. Forty-nine percent of subjects reported clinically significant levels of worst pain. Twenty-one percent of subjects had clinically significant levels of usual pain. Causes of pain were variable and included disease, surgery, and intravenous lines (I.V.). Pain intensity was not significantly related to age, gender, patient type (medical, surgical), or diagnostic category. Children were given significantly less medication than was prescribed, regardless of their reported pain level. Nurses, mothers, and 'no-one' were frequently reported as helping with pain. Medications and nonpharmacological methods were reported as helpful in managing pain. Many children endure unacceptable levels of pain during hospitalization. Pain prevention and management must be more aggressive. Pain assessment should be approached with the same attention as vital signs. Improvements in analgesic prescription and administration practices and non-pharmacological pain control methods are needed.