Objective <p>To investigate the incidence and risk factors for complications after open reduction and internal fixation (ORIF) of acetabular fractures in the elderly.</p> Methods <p>Patients over 60&#xa0;years undergoing ORIF from 2015 to 2023 were reviewed. The primary outcome measure was incidence of medical and surgical complications, including the 1-year mortality rate. Age, gender, fracture pattern, surgical approach and medical comorbidities (using the American Society of Anesthesiologists, ASA grade) were examined for association with fracture reduction, arthritis, hospital stay and patient-reported outcome measures (Hip Disability and Osteoarthritis Outcome Score, HOOS—12).</p> Results <p>The study cohort included 28 males and 24 females (52 patients). 12 patients (23%) experienced a medical complication that needed active treatment and 6 patients (12%) died within the first year. 31 patients (60%) experienced one or more surgery-related complication of which 17 patients (33%) needed revision procedures. Higher age and associated fracture patterns were strongly associated with non-anatomical reduction and post-traumatic arthritis. Surgery needing more than one approach, higher age and ASA grades were associated with prolonged hospital stay. Higher age was the only factor which influenced the HOOS-12 scores negatively.</p> Conclusions <p>A high incidence of medical and surgical complications was observed in elderly patients undergoing ORIF for acetabular fractures. Higher age was consistently associated with complications and poor hip function. More complex fracture patterns, associated medical comorbidities and need for a more extensive surgery were also associated with higher incidence of complications.</p> Level of Evidence <p>IV.</p>