Avian patients are presented commonly to veterinarians for preventive and disease-induced care. Physical examinations commonly are used to assess the overall patient, but this requires manual restraint, which often leads to increased stress and subsequent deleterious effects. To develop a noninvasive evaluation of the stress response in cockatiels (Nymphicus hollandicus), we evaluated the behavior of 26 juvenile cockatiels during their normal daily routine and after an acute stressful event (manual restraint and physical examination). Nonstressed behavior budgets were established by performing quantitative ethograms using 10-minute focal animal sampling methods with point samples recorded every 5 seconds. The ethograms then were repeated after a >10-minute restraint period for physical examination and venipuncture. Plasma corticosterone levels at baseline (<3 minutes) and after stress (>10 minutes) were compared to accompanying behaviors. Plasma corticosterone levels significantly increased after restraint. Overall, reactionary behaviors and inactivity increased, while locomotion, feeding, interaction with the environment, and displays of aggression decreased in the stressed birds. Maintenance behaviors were not significantly different before and after restraint, but the subjective character changed, with stressed birds displaying an increase in behaviors that were short in duration with minimal decrease in vigilance. Our results will be helpful to develop a method of quantifying stress in companion avian patients by using behavioral indicators. However, further study into specific behaviors of significance is needed.