Objective. To conduct a review of the literature on frequency and characteristics of emergency hospital admissions of older people for ill-defined conditions. Background. Emergency hospital admissions for ill-defined conditions are increasing for older people. Despite concern about this trend little is known about the frequency or characteristics of such admissions in emergency medical settings. Method. Relevant papers were identified by searching Medline, Cinahl, Web of Science and other databases. Papers that met inclusion criteria were selected. A descriptive analysis approach was taken. Results. Eighteen studies met the inclusion criteria for the review, all descriptive, survey or cohort studies. None directly investigated the patient group. Some relevant data were available, particularly in relation to frequency of admissions for ill-defined conditions. Conclusions. There is a paucity of research on the patient group, but the evidence available suggests the incidence of these admissions is high in emergency settings and in many countries. Future research on incidence in specific settings, appropriateness of admissions and patient characteristics is urgently required. Relevance to clinical practice. As the population ages increased numbers of older people will be admitted to hospital for ill-defined conditions. Nursing interventions may contribute to future management of these patients.