The purpose of this descriptive study was to determine if older patients discharged from intensive care units (ICU) would be willing to use mobile phone and sensor technology (aka "mobile monitoring") to measure their functional recovery in the posthospitalization period. Semistructured interviews were conducted with 22 older ICU patients and/or their surrogates 24 to 48 hr prior to hospital discharge. While 11 respondents reported they would agree to participate in a future study involving mobile monitoring, an equal number reported they would not participate. Numerous contextual factors were found to affect older adults’ willingness to participate including the belief the research would ultimately benefit themselves or other older adults, concerns about loss of privacy, perception that the research is feasible and valuable, and lack of skills using the technology. Future studies using the mobile monitoring technique with older survivors of a serious illness will require substantial recruitment and educational efforts.