The approach to a newborn or infant who is bleeding can be troublesome for the physician. This lecture will focus upon utilizing the history and screening laboratory to narrow the differential diagnosis in order to provide the most appropriate treatment for this potentially challenging patient population. First, a new approach to understanding the mechanism of coagulation and fibrin deposition will be presented followed by a discussion of the unique aspects of the coagulation system in the infant as well the importance of properly interpreting these laboratory values within the context of the medical history will be reviewed. Next, an overview of possible diagnoses for the bleeding infant will be surveyed with focus upon five specific bleeding conditions commonly encountered in infancy. Finally, general treatment considerations will be explored, followed by a brief offering of case studies when diagnosed based upon the screening laboratory.