Background: among elderly patients, readmission in the month following hospital discharge is a frequent occurrence which involves a risk of functional decline, particularly among frail subjects. While previous studies have identified risk factors of early readmission, geriatric syndromes, as markers of frailty have not been assessed as potential predictors. Objective: to evaluate the risk of early unplanned readmission, and to identify predictors in inpatients aged 75 and over, admitted to medical wards through emergency departments. Design: prospective multi-centre study. Setting: nine French hospitals. Subjects: one thousand three hundred and sixmedical inpatients, aged 75 and older admitted through emergency departments (SAFES cohort). Methods: using logistic regressions, factors associated with early unplanned re-hospitalisation (defined as first unplanned readmission in the thirty days after discharge) were identified using data from the first week of hospital index stay obtained by comprehensive geriatric assessment. Results: data from a thousand out of 1,306 inpatients were analysed. Early unplanned readmission occurred in 14.2% of inpatients and was not related with sociodemographic characteristics, comorbidity burden or cognitive impairment. Pressure sores (OR = 2.05, 95% CI = 1.0–3.9), poor overall condition (OR = 2.01, 95% CI = 1.3–3.0), recent loss of ability for self-feeding (OR = 1.9, 95% CI = 1.2–2.9), prior hospitalisation during the last 3 months (OR = 1.6, 95% CI = 1.1–2.5) were found to be risk factors, while sight disorders appeared as negatively associated (OR = 0.5, 95% CI = 0.3–-0.8). Conclusions: markers of frailty (poor overall condition, pressure sores, prior hospitalisation) or severe disability (for self-feeding) were the most important predictors of early readmission among elderly medical inpatients. Early identification could facilitate preventive strategies in risk group.