Global competition, crying off profit margin, customer requirement for high quality product at near to the ground cost and other economic factors set in motion the manufacturer to reduce their production cost without concession of quality in order to stand up in business area. Defect or wastages reduction is the initial step to reduce production cost as well as improve the quality. Higher quality comes with the reduced cycle time by reducing alternation. Apprehensive this issue, this work walks around the use of DMAIC methodology of six sigma to lessen the defect rate in sewing section of FCI (BD) LTD. Throughout five phases of DMAIC methodology, named Define, Measure, Analyze, Improve and Control, this approach minimizes defects analytically. In different phases, different types of six sigma tools were exercised. Pareto analysis was acted to identify the top defects and root causes of those defects were sensed. These were done for Ladies' tops and trousers. Brainstorming and literature review helped to endow with some potential solutions to overcome the problem. With the remedial action and implementation in pilot run, the result found is very noteworthy. The defect percentage has been reduced from 11.67 to 9.672 and as a result, the sigma level has been upgraded from 2.69 to 2.8.