We retrospectively analyzed data of 38 elderly patients, each with an underlying disease, to evaluate peramivir safety and efficacy. Six patients (15.8%) experienced adverse events, all tolerated. Median time from administration until the return to normal temperatures was 31.5 h (95% CI: 22.4-40.6). Results confirm intravenous peramivir's usefulness. Copyright (C) 2017, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.