Objectives: - This study was conducted in a level I trauma centre to review the outcome of surgical repair of Traumatic Diaphragmatic Rupture (TDR) and to identify the predictors of mortality and hospital stay. Methods: - Between January 1990 and January 2001, consecutive patients with TDR and ISS (Injury Severity Score) > 12 were identified from a prospective trauma registry. Hospital charts of all eligible patients were reviewed for demographic data, mechanism of injury, mode of diagnosis, type of surgical repair, need for ventilatory support, ICU & hospital stay and mortality. We conducted a stepwise regression analysis (logistic regression for mortality, and multiple regressions for hospital stay). Results: - Of the 59 patients included in the study 44 (75%) were males. Their mean age was 43±18years and their average ISS was 39 ± 15 Blunt injuries (85%) and left sided ruptures (73%) were the most common. Frontal and side impacts were equally distributed. Twenty eight (66%) patients were drivers. Forty five (79%) patients were ventilated following the diaphragm repair. A significantly higher proportion of patients with blunt injuries required ventilatory support compared with penetrating injuries (93% vs. 38%, P <0.05). The mortality rate was 7%. Older age was a significant predictor of mortality (Odds ratio = 1.2, 95% CI = 1.1-1.4, P = 0.04). ISS (Odds ratio =1.1, 95% CI = 0.98 -1.2, P = 0.08) and need for ventilation (Odds ratio=1.02, 95% CI = 0.97-1.12, P=0.09) revealed trends towards mortality, but were not statistically significant. Hospital stay was predicted by the ISS (B=0.09, P=0.05) score and need for postoperative ventilatory support (B=0.26, P=0.04). Conclusion: - This is the largest Canadian series from a single trauma centre. It revealed that older age is a major predictor of mortality whereas the need for ventilatory support did not predict the overall mortality.