Introduction: Improvements in living conditions and progress in medical management have resulted in better ​quality of life and longer life expectancy. Therefore, the number of older people undergoing surgery is increasing. Frailty is often described as a syndrome in aged patients where there is augmented vulnerability due to progressive loss of functional reserves. Studies suggest that frailty predisposes elderly to worsening outcome after surgery. Since emergency surgery is associated with higher mortality rates, it is paramount to have an accurate stratification of surgical risk in such patients. The aim of our study is to characterize the clinico-pathological findings, management, and short-term outcome of elderly patients undergoing emergency surgery. The secondary objectives are to evaluate the presence and influence of frailty and analyze the prognostic role of existing risk-scores. The final FRAILESEL protocol was approved by the Ethical Committee of "Sapienza" University of Rome, Italy. Methods and analysis: The FRAILESEL study is a nationwide, Italian, multicenter, observational study conducted through a resident-led model. Patients over 65 years of age who require emergency surgical procedures will be included in this study. The primary outcome measures are 30-day postoperative mortality and morbidity rates. The Clavien-Dindo classification system will be used to categorize complications. Secondary outcome measures include length of hospital stay, length of stay in intensive care unit, and the predictive value for morbidity and mortality of several frailty and surgical risk scores. The results of the FRAILESEL study will be disseminated through national and international conference presentations and peer-reviewed journals. The study is also registered at ClinicalTrials.gov (ClinicalTrials.gov Identifier: NCT02825082).