Background There have been conflicting reports regarding whether the number of rib fractures sustained in blunt trauma is associated independently with worse patient outcomes. We sought to investigate this risk-adjusted relationship among the lesser-studied population of older adults. Methods A retrospective review of the National Trauma Data Bank was performed for patients with blunt trauma who were ≥65 years old and had rib fractures between 2009 and 2012 (N = 67,695). Control data were collected for age, sex, injury severity score, injury mechanism, 24 comorbidities, and number of rib fractures. Outcome data included hospital mortality, hospital and intensive care unit durations of stay, duration of mechanical ventilation, and the occurrence of pneumonia. Multiple logistic and linear regression analyses were performed. Results Sustaining ≥5 rib fractures was associated with increased intensive care unit admission (odds ratio: 1.14, P < .001) and hospital duration of stay (relative duration: 105%, P < .001). Sustaining ≥7 rib fractures was associated with an increased incidence of pneumonia (odds ratio: 1.32, P < .001) and intensive care unit duration of stay (relative duration: 122%, P < .001). Sustaining ≥8 rib fractures was associated with increased mortality (odds ratio: 1.51, P < .001) and duration of mechanical ventilation (relative duration: 117%, P < .001). Conclusion In older patients with trauma, sustaining at least 5 rib fractures is a significant predictor of worse outcomes independent of patient characteristics, comorbidities, and trauma burden.