Abstract: OBJECTIVE: To understand the clinical characteristics, strain distribution and treatment regression of lower respiratory tract fungal infections in mechanically ventilated patients in the emergency intensive care unit (EICU). METHODS: To retrospectively analyze the clinical data of patients with lower respiratory tract fungal infections occurred in the EICU of Xinhua Hospital from October 2007 to December 2008 by mechanical ventilation. RESULTS: Lower respiratory tract infections occurred in 80 of 124 mechanically ventilated patients, with an incidence of 64.5%, including 21 cases (26.2%) with fungal infections, all of which were Pseudomonas spp. (11 cases of Pseudomonas albicans, 5 cases of Pseudomonas tropicalis, 3 cases of Pseudomonas smoothus, and 2 cases of Pseudomonas subsmoothus); Apache II score for fungal infections compared with non-fungal infections. 21.89 vs 17.36, mean mechanical ventilation: (20.5 vs 14.2) d, length of ICU stay: (22.5 vs 18.4) d, mortality: 33.3% vs 15.2%, all higher than non-fungal infection cases; 11 cases of Pseudomonas albicans without 1 death and 7 cases of non-Pseudomonas albicans deaths. Conclusion The incidence of concomitant lower respiratory tract fungal infections in mechanically ventilated patients in EICU is high, mainly Pseudomonas aeruginosa infections, with Pseudomonas albicans predominating. In contrast, non-Pseudomonas albicans infections have a high morbidity and mortality rate and are resistant to fluconazole, suggesting that effective interventions should be taken early.