Veterinarians treating birds are faced with challenges often not encountered by their counterparts treating dogs and cats. Many birds are presented to veterinarians only when near terminally ill, and a quick answer is often the difference between life and death. Birds are often limited in their range of expression of clinical signs and many clinicians, through no fault of their own, lack the experience to conduct a thorough physical examination. The combination of these factors has led to an increasing tendency in avian medicine to conduct exhaustive diagnostic tests on patients, often with scant attention being paid to a complete history and a careful physical examination, and with little attempt to refine or focus the diagnostic efforts. The selection of diagnostic tests should be based on a solid understanding of the species in question, the results of a thorough history taking and physical examination, and a shortened list of probable differential diagnoses based on this work up.