Background: Mucormycosis is a life-threatening fungal infection with high mortality in critically ill patients. Clinical manifestations and outcomes of mucormycosis in intensive care units (ICUs) remain poorly investigated. Methods: We conducted a multicenter retrospective study including 43 adult patients with confirmed mucormycosis admitted to 14 tertiary ICUs between January 2014 and May 2022. Clinical characteristics, diagnostic approaches, treatment strategies, and outcomes were analysed. Results: The mean age was 56.8 +/- 16.2 years, with 16/43 (37.2%) female patients. The 28-day survival rate was 46.5% (20/43). Lung involvement was predominant (29/43, 67.4%), and 29/43 (67.4%) patients received amphotericin B therapy. Survivors showed significantly better treatment response compared to non-survivors (16/20, 80% vs. 4/23, 17.4%, p < 0.001). Non-survivors demonstrated significantly higher levels of aspartate aminotransferase, C-reactive protein, and white blood cells, along with lower albumin levels. Metagenomic next-generation sequencing (mNGS) was associated with a shorter time to diagnosis. Multivariate analysis identified age, respiratory failure, time from symptom onset to diagnosis, and antifungal treatment response as independent predictors of 28-day mortality (AUC = 0.852). Conclusion: In critically ill patients with mucormycosis, early diagnosis and prompt targeted therapy are crucial determinants of survival, with our newly developed prediction model providing a practical tool for risk stratification, while mNGS shows promise in expediting diagnosis.