Purpose <p>Early surgical site infection (SSI) after orthopedic trauma surgery remains a severe postoperative complication associated with increased morbidity and mortality. However, data specifically focusing on geriatric trauma patients remain limited. The aim of this study was to evaluate mortality, infection control, and postoperative complications associated with early SSI in patients older than 75 years, and to identify factors associated with mortality and infection persistence.</p> Methods <p>A retrospective monocentric observational cohort study was conducted in an academic orthopedic trauma center. All consecutive patients aged ≥ 75 years treated for an early SSI occurring within 30 days after surgically managed fractures between January 2016 and June 2025 were included. Demographic, surgical, microbiological, and infectious data were collected. Primary outcome was all-cause mortality during follow-up. Secondary outcomes included infection control, postoperative complications, infection persistence or recurrence, and functional outcome assessed using parker mobility score. Univariate analysis was performed using relative risks (RR) with 95% confidence intervals (CI).</p> Results <p>Forty patients were included, with a mean age of 84.5 years (range 76–95). Twenty-three patients (57.5%) had an ASA score ≥ 3. Staphylococcal species were identified in 65% of infections, while 45% were polymicrobial. Infection control was achieved in 26 patients (65%). Mortality reached 25% during follow-up. Twenty-eight patients (70%) experienced at least one postoperative complication, and eight patients developed chronic infection. ASA score ≥ 4 (RR = 3.6; 95% CI [1.4–9.28]), severe renal insufficiency (RR = 4; 95% CI [1.81–8.85]), and polymicrobial infection (RR = 3.61; 95% CI [1.12–11.62]) were significantly associated with mortality. Delay to surgical debridement ≥ 10 days was associated with infection persistence or recurrence (RR = 4.67; 95% CI [1.49–14.59]). Median Parker Mobility Score significantly decreased from 6.0 preoperatively to 4.0 at final follow-up (<i>p</i> &lt; 0.001).</p> Conclusion <p>Early SSI after trauma surgery in patients older than 75 years is associated with substantial mortality, high complication rates, and significant functional deterioration. Severe comorbidities, renal insufficiency, and polymicrobial infection were associated with mortality, while delayed surgical management was associated with infection persistence, while delayed surgical management is associated with persistent infection. Early multidisciplinary management and optimized perioperative care may improve outcomes in this vulnerable population.</p> Level of evidence <p>Level IV, retrospective cohort study.</p>