The purpose of this study was to determine the types of cases residents select for morning report discussion and the educational value of postdischarge follow-up of unknown cases. Between April and December of 1994, at Cardinal Glennon Children's Hospital in St. Louis, Missouri, random, resident, and group-selected patients listed at morning report were followed up throughout hospitalization. Patients were categorized based upon whether or not their morning report and discharge diagnoses were the same or different. Patients discharged without a diagnosis were followed up by chart review at 6 months to determine whether a diagnosis had been made. Data were analyzed by Chi-square analysis with Bonfferoni adjustment factor for multiple comparisons. Residents were more than two times more likely to select cases for discussion in which the diagnosis changed during hospitalization (P < 0.01). The 6-month follow-up yielded new diagnoses in only 21% of previously unknown cases. We concluded that residents do an exceptional job of selecting difficult diagnostic cases for discussion at morning report. Postdischarge follow up of unknown cases adds little new information for discussion at morning report.