Background: The deficits in the self-care of older people are often associated with a loss of autonomy and if care is not provided in the home environment by relatives or professional caregivers, then the self-care deficits may result in the admission to a residential care facility (RCF). On the other hand, in industrialized countries, the recruitment and long-term retention of professional caregivers are becoming increasingly difficult. Technical aids such as sensor technology (SeTe) could solve this dilemma and improve the autonomy, the quality of life, and the safety of the residents. Objectives: To analyze the nursing problems targeted in the studies, where was the SeTe used, and why has it been chosen, the technical limitations of SeTe and whether the studies contain ethical considerations. Design: This review followed the Cochrane Collaboration methods for systematic reviewing. The databases EBSCOhost (which includes CINAHL, MEDLINE, and PsycINFO), Web of Science, Cochrane Library, and Google Scholar were searched. Methods: This critical systematic review analyzes publications on SeTe if the nursing problems referred to by scientists have been in connection with residents of RCFs. Studies that focused on participants in hospitals and home environments or those using gaming consoles or medical applications were excluded. Results: Of the 49 studies included, 31% used only accelerometers, 20% used cameras, and 29% combined various types of SeTe devices. The use of various SeTe was beneficial, possibly because the more perspective data are combined. 51% preferred non-wearable SeTe devices, ⅔ preferred the permanent surveillance by SeTe devices. The nursing problems which the research teams concentrated on were fall risk, immobility, agitation and sleep problems. Only ¼ of the studies mention current or potential ethical considerations regarding the surveillance of residents by SeTe devices. Conclusion: It is gratifying that the international interest in researching SeTe in RCFs has increased. Ethical dilemmas were hardly discussed. The future use of SeTe in RCFs is certainly desirable and unavoidable, but consulting the residents, professional caregivers, and nursing scientists about their requirements for useful and necessary technical surveillance first seems usefull. Relevance to Clinical Practice: Currently RCFs should continue to use the SeTe cautiously. Professional caregivers in RCFs should be able to convey the growing self-image of nursing into similar SeTe research projects.