In a prospective study of cases of severe acute respiratory infections seen at the University College Hospital, Ibadan over a 30-month period, 39 cases were found to have acute upper airway obstruction; out of this number, acute laryngotracheobronchitis (croup) accounted for 35 (90%). The ages of the 35 ranged from 2 to 53 months with 86% being less than 3 years old, while there was a male preponderance (M:F ratio, 1.7:1). Croup was associated with bronchopneumonia in 29%, measles in 2.9%, and with both in 40% of the 35 cases. The mean respiratory rate in patients in whom croup co-existed with measles and pneumonia was significantly higher than that in patients with croup alone (P < 0.001). Six (55%) of the eleven viral identifications made were Parainfluenza virus types 1-3, while Respiratory syncytial virus was identified in three patients. Of the 18 blood cultures done, only one was positive, yielding Klebsiella pneumoniae in a two-year old undernourished child with associated measles and bronchopneumonia. Mortality was 11%; all the four children who died had associated bronchopneumonia, which complicated measles infection in three. The findings in this study support the view that antibiotic therapy is not routinely indicated in the management of croup. Furthermore, measles and bronchopneumonia were identified as indicators of poor prognosis requiring extra care in management.