IntroductionThe primary aim is to validate earlier suggested risk factors and to find new associated risk factors for (30-day) mortality after a hip fracture in the frail population. The secondary aim is to determine the factors associated with perioperative complications. At last we want to develop and validate a more specific 30-day mortality prediction tool compared with the Nottingham Hip Fracture Score. The 30-day mortality prediction can help inform surgical risk and guide shared decision-making among patients, family and physicians.Methods and analysisThe study is designed as a prospective multicentre cohort study within the area of Rotterdam, the Netherlands starting from January 2018. All patients over 65 years of age, with an acute proximal hip fracture, are included. Treatment of patients will be by standard practice of care using the latest national and international guidelines. Inclusion will be continued at least until January 2021 and including at least 2500 patients. In this large cohort we hope to have sufficient strength and quality to identify risk factors of 30-day mortality and to compare them to known risk factors in literature. Moreover, we plan to develop and validate a 30-day mortality prediction tool, which identifies patients with a high probability of 30-day mortality.Ethics and disseminationEthical approval for this protocol was given by the Ethics Committee of the Maasstad Hospital (TWOR). Patient data are stored anonymously using the Castor data management system. No external funding is used for this study. Results will be published in peer-reviewed publications and at international conferences.Trial registration numberNL8313.