The objective of this study was to assess the ability of citizens in a senior living community (SLC) to perform adequate cardiopulmonary resuscitation (CPR) and appropriately utilize an automated external defibrillator (AED) in a simulated cardiac arrest scenario (SCAS). This study was a prospective, observational study; a convenience sample of SLC residents aged > 54 years was enrolled. Subjects were presented with a SCAS (adult mannequin, bystander available to assist, AED visible). Subjects' skills were rated in standardized fashion. For statistical analysis, 95% confidence intervals (CIs) were calculated as appropriate. There were 51 subjects; 69% were female; mean age was 64 years; 86% were without disabilities. Pre-retirement professions included: medical (13.7%), office/sales (41.2%), and engineer/science (15.7%). Subjects had previous American Heart Association first-responder training (CPR and AED use) as follows: none (22%), within 0 to 6 months (47%), 7-12 months (4%), > 12 months (27%). During the SCAS, subjects performed inconsistently on the various links in the chain of survival. Although most subjects (94%; 95% CI 84-99%) checked for unresponsiveness, only 62.8% (95% CI 48-76%) also specified "call 911 and bring me the AED." Most subjects (88%; 95% CI 76-96%) started chest compressions, however, only a minority provided high quality chest compressions (29%; 95% CI 17-44%). With respect to AED skill performance, we noted the following: 94% (95% CI 84-99%) of subjects removed the patient's clothing, 90% (95% CI 79-97%) turned the device on, 94% delivered a shock as directed, and 82% continued CPR if "no shock indicated" by AED (95% CI 69-92%). Performance was less satisfactory for the following: only 39.2% (95% CI 26-54%) continued chest compressions after AED arrival, 60.8% (95% CI 46-74%) of subjects correctly attached electrodes, and 6% (95% CI 1-16%) verbalized "clear" in advance of shock. Although many members of our sample SLC had prior training, they frequently failed to adequately perform some key steps in the SCAS. Recent efforts to place AEDs in SLCs should be augmented by a plan to adequately train residents and other available individuals (e.g., staff) in CPR/AED use.