BACKGROUND Adverse events (AEs) are a persistent and an important reason for Intensive Care Unit (ICU) admission. They lead to death, disability at the time of discharge, unplanned ICU admission (UIA), and prolonged hospital stay. They impose large financial costs on health-care systems. OBJECTIVE This study aimed to determine the incidence, patient characteristics, type, preventability, and outcome of UIA following elective surgical AE. METHODS This is a single-center prospective study. METHODS Analysis of 15,372 elective surgical procedures was performed. We defined UIA as an ICU admission that was not anticipated preoperatively but was due to an AE occurring within 5 days after elective surgery. METHODS Descriptive analysis using SPSS software version 18 was used for statistical analysis. RESULTS There were 75 UIA (0.48%) recorded during the 2-year study period. The average age of patients was 54.64 ± 18.02 years. There was no sex predominance, and the majority of our patients had an American Society of Anesthesiologist classes 1 and 2. Nearly 29% of the UIA occurred after abdominal surgery and 22% after a trauma surgery. Regarding the causes of UIA, we observed that 44 UIA (58.7%) were related to surgical AE, 24 (32%) to anesthetic AE, and 7 (9.3%) to postoperative AE caused by care defects. Twenty-three UIA were judged as potentially preventable (30.7%). UIA was associated with negative outcomes, including increased use of ICU-specific interventions and high mortality rate (20%). CONCLUSIONS Our analysis of UIA is a quality control exercise that helps identify high-risk patient groups and patterns of anesthesia or surgical care requiring improvement.