OBJECTIVES: Our aim was to estimate the hospitalization length of stay (LOS) and risk of death within hospitalization, associated with the occurrence of post-operative residual curarization (PORC) and adverse events (AE) possibly or probably related to neuromuscular blockade reversal agents (NMBRA) use. METHODS: Data was obtained from hospitalizations occurring in Portuguese public hospitals in 2007. Surgical procedures from (ICD-9-CM CSP codes): central nervous (01-05), endocrine (06-07), respiratory (30-34), cardiovascular (35-39), hematologic and lymphatic (40-41) and digestive (42-54) systems were selected due to their high potential for NMBRA use. According to clinical expertise and ICD-9 diagnosis classification, AE and events PORC were grouped into the following outcomes: bronchospasm, dysphagia or dyspepsia, cardiac dysrhythmias, tachycardia, hypertension, hypotension, xerostomia, nausea, vomiting or abdominal pain, central nervous system complications and allergic, psychological, respiratory, sensation and visual disturbances. Data consisted of admission and discharge date, age, gender, primary and secondary diagnosis, primary and secondary surgical procedures. No data was available regarding the type of NMBRA used. Within hospital, risk of death was estimated with parametric survival (Weibull) regression models. LOS was estimated through negative binomial regression models. RESULTS: The analysis included 136,150 surgical procedures (55.0% female and mean(SD) age 54.2(18.9) years). Rates of AE and PORC were 25.5% and 3.0%, respectively. Crude death rate was 2.8%. The risk of death was 1.3 (95%CI: 1.2-1.4) times higher in patients with AE and 2.0 (95%CI: 1.9-2.2) times higher in patients with PORC, adjusted for other covariates. The mean LOS was 5.3 days (<30 days, n=130,254). LOS was significantly increased both in patients with at least one AE (2.2 days, 95%CI: 2.1-2.4) or at least one PORC event (7.4 days, 95%CI: 6.7-8.2). CONCLUSIONS: Post-operative residual curarization and adverse events possibly or probably related to neuromuscular blockade reversal agents use are associated with increased inpatient death and extended hospital length of stay.