Background: To estimate how often ADE of an empirically prescribed antimicrobial therapy is performed in the critical ill patients and the pattern of de-escalation and To determine the effect of ADE on day-7 clinical cure and 28 day mortality following initiation of empirical therapy. Method: In a prospective observational study conducted from november 2022 to January 2024, researchers examined how antimicrobial de-escalation (ADE) affected clinical outcomes in adult ICU patients who were receiving empirical antimicrobial treatment for bacterial infections. ADE was defined in two ways: either by discontinuing an antimicrobial when combination therapy was used or by replacing an antimicrobial to narrow its spectrum within the first three days of treatment. To account for time-dependent confounding factors, inverse probability (IP) weighting was applied in estimating the effect of ADE on the likelihood of clinical cure. Result: The study included 200 patients from ICUs of HAHC hospital. Combination therapy was used for 50% of these patients, and 26% received carbapenems. Within the first three days of empirical therapy, 16.5% of patients underwent antimicrobial de-escalation (ADE), 63.5% had no change, and 21% experienced changes other than ADE. Conclusion: Antimicrobial de-escalation (ADE) was used infrequently among critically ill patients with infections. The observational data indicated that ADE did not appear to negatively affect clinical cure rates compared to situations where no ADE was applied. Nevertheless, there is likely residual confounding that may influence these findings.