OBJECTIVE To assess the cost per life saved of equipping long-term care facilities (LTCFs) with automated external defibrillators (AEDs). METHODS Outcomes for cardiac arrests within LTCFs were retrieved for 1994 to 1997 from a comprehensive out-of-hospital cardiac arrest registry in a mid-sized U.S. city. The total expense for all LTCFs to obtain and maintain AEDs and to educate and maintain staff skill was estimated for a theoretical four-year period. The cost per life saved to the time of hospital discharge was calculated based on an estimated survival rate of 25% of patients found in ventricular fibrillation (VF) with placement of AEDs in LTCFs. A sensitivity analysis that varied survival rates and costs was conducted. RESULTS Over four years, there were 160 actual arrests in 43 LTCFs, with a hospital discharge survival rate of 2/160. Twenty of 160 presented to emergency medical services in VF. Training costs for four years were $1,225 per AED. Purchase and maintenance expenses for one AED over four years were $3,941. Placing AEDs in LTCFs would cost $87,837 per life saved if 25% of patients found in VF survived to hospital discharge. Sensitivity analysis using survival rates of 5%, 15%, and 35% established the cost per life saved at $439,184, $146,395, and $62,741, respectively. When costs were calculated at one-half and twice the estimated expense, the cost per life saved was $43,918 and $175,674, respectively. CONCLUSIONS Placing AEDs in LTCFs is cost-effective at $87,837 per life saved, if a hospital discharge survival rate of 25% of patients in VF can be achieved.