Introduction: In modern clinical practice, the use of sedatives in patients on mechanical ventilation is an integral part of critical care. Sedative application plays an important role in maintaining patient stability, reducing agitation, and facilitating the tolerance of mechanical ventilation. The assessment of sedation depth is becoming increasingly important in clinical practice for better monitoring and adjusting sedation therapy in ICU patients. In this final paper, a study was conducted on the frequency of use of specific types of sedatives and methods of sedation depth assessment tools in patients on invasive mechanical ventilation. Aim: To investigate the frequency of use of specific types of sedatives, preferences between continuous intravenous infusion and bolus technique, and the application of entropy monitoring and RASS scales in patients on invasive mechanical ventilation. Methods: The study included 125 patients who stayed in the Department of Anesthesiology, Reanimatology, Intensive Care, and Pain Management of Karlovac General Hospital from January 1, 2023, to December 31, 2023. Patients were divided into two groups: Group A (short-term invasive mechanical ventilation (24-96 hours)) and Group B (long-term invasive mechanical ventilation (>96 hours)). The study was conducted through retrospective analysis of data from BIS and patient medical histories after obtaining approval from the ethical committee of Karlovac General Hospital. Results: The most commonly used sedative was midazolam, the most frequent method of application was the bolus technique, and the assessment of sedation depth using entropy monitoring was applied in only 22.4% of patients, while the RASS scale was used in 25.6% of patients included in the study. Conclusion: The study results indicate that midazolam is the most commonly used sedative in patients on invasive mechanical ventilation. The application of continuous infusion sedatives was more frequent in patients with short-term invasive mechanical ventilation, while methods for assessing sedation depth (entropy monitoring, RASS scale) were also more frequently used in patients with short-term invasive mechanical ventilation compared to those on long-term mechanical ventilation.