Invasive fungal infections (IFIs) are serious complications in elderly adults. Caspofungin may provide a useful therapeutic option for elderly patients with or at high risk for IFIs. We retrospectively compared efficacy and safety outcomes in elderly (> or = 65 years of age) and non-elderly patients in three clinical trials of caspofungin: a double-blind, randomized trial versus amphotericin B for documented invasive candidiasis (IC); an open-label, non-comparative study of definite or probable invasive aspergillosis (IA); and a double-blind, randomized trial versus liposomal amphotericin B as empirical therapy (ET) in febrile neutropenic patients. A total of 159 elderly patients with a median age of 71 years (range, 65-84) received caspofungin in these studies. The median duration of caspofungin therapy was 12 days for IC and ET, and 28 days for IA. Point estimates for the favorable response rates to caspofungin were numerically higher in elderly versus non-elderly patients with IC (83% vs. 68%) or IA (64% vs. 44%) and were similar in patients receiving ET (36% vs. 34%). Adverse events related to caspofungin occurred in generally similar proportions of elderly versus non-elderly patients with IC (clinical, 33% vs. 27%; laboratory, 17% vs. 29%), with IA (clinical, 7% vs. 13%; laboratory, 13% vs. 14%), or receiving ET (clinical, 47% vs. 47%; laboratory, 24% vs. 22%). Nephrotoxicity and infusion-related toxicity developed in comparable proportions of elderly and non-elderly caspofungin recipients in all three studies. In this post-hoc analysis, caspofungin appeared to be as efficacious and well tolerated in elderly patients as in non-elderly patients.