Each company has the goal of increasing profits by fulfilling consumer demand in accordance with predetermined quality standards. By seeking continuous quality improvement, it can increase product competitiveness with competing products. Myristic acid is a product of PT. XYZ oleochemicals. Based on current quality data, sometimes the resulting myristic acid products do not meet consumer specifications, so they have to be reprocessed, which results in increased production costs. To overcome this, we need a method that can continuously improve quality. The six-sigma method is a production control method that aims to improve product quality through the DMAIC (Define, Measure, Analyze, Improve, and Control) stages. The use of the six-sigma method in this study shows that the critical quality that causes the product not to meet specifications is in the production process, namely those caused by materials, mans, and machines. In addition, measurements show an average sigma level of 3.87, so improvement and control are needed.