The purpose of this study is to examine quality control in the sorbitol industry using the six-sigma method to determine the causes of wasteful production costs and factors that influence them. This research collected 300 data with the details of 150 data in each phase, before and after the implementation of improvement action, and interviewed 12 employees in the sorbitol department. Six sigma approach consists of five phases: define tested by statistic descriptive, measure analyzed by process capability, analyze phase analyzed by fishbone diagram and action priority matrix, improve analyzed by process capability, and control phase tested by X Bar R chart. The results of this study are DPMO (Defect Per Million Opportunity) decreased from 994,497 to 543,058, sigma level increased from - 1.04 to 1.39, standard deviation from 0.0072196 to 0.01, Pp (Process Performance) from 0.11 to 0.22, Ppk (Process Performance Index) from - 0.85 to 0.09, average reducing sugar from 0.11 to 0.14, and the use of nickel from 298 to 221 Kg.