Background: Controversies regarding infant feeding and childhood wheezing may result from insufficient differentiation among various feeding modes.Objectives: We conducted prospective analyses of associations between the repeated ascertainment of feeding mode and wheezing in infancy.Methods: The Infant Feeding Practices Study II (2833 infants) provided data on coughing/wheezing episodes (CWEs) at 8 time points and feeding modes at 9 time points from months 1 to 12.