Six Sigma has been viewed as a successful methodologyof process improvement and variation reduction. Thefundamental objective of the Six Sigma methodology isthe implementation of a measurement-based strategy thatfocuses on process improvement and variation reductionthrough the application, which can be accomplished bythe use of Six Sigma DMAIC process. The Six SigmaDMAIC process (define, measure, analyze, improve,control) is a process eliminating defects (driving towardssix standard deviations between the mean and nearestspecification limit) in any process – from manufacturingto transactional and from product to service. This paperpresents the application of using Six Sigma in a PrintedCircuit Board Assembly industry (PCBA). Based on theobservation, the main problems of the PCBA case studywas incurred in the surface mount technology (SMT)process. The problem includes mainly in quality problem.The use of Six Sigma DMAIC process is applied to shrinkthe problem. Based on the study, it is proof that Six Sigmais an effective tool to increase in product quality.