Studies of the effects of ambient noise on animals have found variable results. A study was conducted at the Smithsonian's National Zoological Park to determine what effect short-term demolition work would have on the behavior and cortisol excretion of giant pandas. Behavioral and endocrine differences were examined during the presence and absence of demolition work being conducted on an adjacent exhibit complex. High frequency noise was significantly louder on work days compared to non-work days. Panda activity budgets differed significantly between work and post-work periods, although in different ways. The male's use of substrates and locations that might be associated with refuge or shelter changed during the study; the female did not show similar changes. He spent more time in the enclosure adjacent to the work site rather than a more distant enclosure during the demolition period whether work was occurring or not. The behavior of both animals was more often characterized as “restless” during, as opposed to before or after the work period. In general, cortisol excretion increased during the study in both animals but this was likely a seasonal effect in the male. In many cases, significant short-term increases in cortisol were temporally associated with certain kinds of construction noises or specific physiological events. Variability in cortisol secretion fluctuated during the study for both animals but in differing patterns. These results demonstrate that demolition noise was associated with behavioral and some physiological changes in giant pandas, and these changes were individual-specific. Zoo Biol 0:1–18, 2006. © 2006 Wiley-Liss, Inc.