Polyester short cut fiber is a textile industry which is rarely explored or researched. This research explains the necessary steps of improvement using Six Sigma method to reduce the nonconform-ing products in a polyester short cut fiber manufacturing in Indonesia. An increased noncon-forming products in the shortcut fiber production process created some quality problems from January to May, 2015. Define, measure, analysis, improve, control (DMAIC) steps were im-plemented to determine root cause of the problems and to improve production process using sta-tistical approach. The results of Six Sigma improvement has indicated that the process capability was increased from 2.2 to 3.1 sigma, savings $18,394.2 USD per-month.