<p>Since long laboratories have been burdened heavily with the pressure of producing correct and timely reports. For the benefit of patients and doctors, it is imperative to emphasize the quality of results provided. Even with best practices adopted, one cannot ignore the possibility of errors that exist in the laboratory in the pre-examination, examination and post-examination phase. Error quantification can be done in variety of ways using quality indicators. Six sigma is one of these methods, classifying performance parameters as outstanding, excellent, good and poor in terms of defects per million opportunities in the pre- and post-examination phases and a sigma score with the help of bias%, CV% and total allowable error in the examination phase. The novelty of using lean Six sigma in laboratories is in its specific adaption to deal with the special difficulties and demands of laboratory settings along with more rapid and precise diagnostic results, thereby enhancing patient care and satisfaction. As optimistic as it sounds, there are obstacles associated with implementing lean six sigma also. Clinical laboratories frequently find it difficult to commit the capital and staff required for extensive six sigma projects. Thus precise measurements and benchmarks to assess the success of changes that have been put into place are some of the challenges that cannot be overlooked. Once accomplished, though, its advantage is undeniable. We have endeavored to evaluate lean six sigma at all three stages pre- examination, examination and post examination, discussing their challenges and providing guidance to others through a range of case studies.</p>