Proficiency Testing (PT) is defined as the evaluation of participants performance against pre-established criteria by means of inter-laboratory comparisons. Proficiency tests are necessary part of quality control activities. It intends essentially to enable the participant to detect unsuspected errors in their analytical systems so as to produce quality results. The laboratories having NABL accreditation as per ISO-17025:2005 need successful participation in proficiency testing schemes in all parameters as per their four year plan. While those who are applying for accreditation need successful participation in at least one PT programme prior to gaining accreditation in each discipline applied. This PT scheme facilitates by providing an opportunity to fulfil the mandate.