ABSTRACTObjectives:to describe the Lean Six Sigma implementation process to improve the discharge process in a Brazilian health institution’s ICU.Methods:prospective study following the Define-Measure-Analyse-Improve-Control project development method. This method consists of five phases, namely: project definition, measurement of the starting point and data collection, analysis of results, improvement in processes, and statistical control.Results:applying Lean Six Sigma methodology following the Define-Measure-Analyse-Improve-Control in the discharge process from the intensive care unit to the inpatient unit was effective in improving processes. This improvement represented a reduction in the mean patient transfer time to the inpatient unit from 189 minutes to 75 minutes, representing a 61% improvement in discharge time.Conclusions:this article demonstrates the effectiveness of applying Lean Six Sigma methodology to improve the discharge flow in a critical unit, resulting in time and waste reduction.