Objective Systemic lupus erythematosus (SLE) is a clinically heterogeneous autoimmune disease, and in some conditions, admission to the intensive care unit (ICUs) is required. This study describes the clinical and prognostic factors in SLE patients admitted to the ICU. Methods We conducted a retrospective study that reviewed all clinical records of patients with SLE admitted to the ICU between 2011 and 2018. Results We evaluated 188 patients, with 279 ICU admissions. Most patients were female ( n = 159; 84.57%) with a median age of 35 years (interquartile range (IQR) = 25–48 years). Infection was the leading cause of admission in 77 (27.60%) cases, followed by lupus flare. The average length of hospitalization was 5 days (IQR 3–11 days), and the SLE Disease Activity Index 2000, Acute Physiology, Age and Chronic Health Evaluation (APACHE II), and Sequential Organ Failure Assessment (SOFA) scores were 9 (IQR 2–17), 14 (IQR 10–17), and 3 (IQR 2–5), respectively. Non-survivors presented with higher APACHE II and SOFA scores. Infection was the leading cause of mortality ( n = 38; 20.21%), and predictors of mortality included invasive mechanical ventilation, vasoactive medication requirement, higher SOFA scores, and antiphospholipid syndrome comorbidity. Conclusions We found that infection was the leading cause of ICU admissions and mortality in patients with SLE. Factors identified here as predictors of mortality should be accurately identified at admission for the prompt treatment of SLE patients.