Bureau of Laboratory Accreditation, Department of Science Service provided a training workshop “Assessor Training Course for PTP Accreditation” which was held at Room 320, Floor 3, Analytical Chemical Building between 9^th and 11^th August 2023. On this occasion, Dr. Patom Sawanpanyalert (M.D, PhD), a Director General of Department of Science Service (DSS), Ministry of Higher Education, Science, Research and Innovation (MHESI) presided the opening of the workshop. The workshop was run by honorably special guests, namely Mrs. Chantarat Vorasapavit, Ms. Pornpan Pantipamporn,  Associate Prof. Krunchit Jutprasong, Institute of Nutrition, and Associate Prof. Srisanit. The trainees who joined the workshop were of those had extensively work in the areas of proficiency testing/calibration as well as medical laboratory. The aim of the workshop was to prepare the trainees to be ready for being an assessor for proficiency testing provider accreditation according to APAC: Guidelines on Training Course for Assessors (APAC CBC-002). The workshop also aimed to enhance the their professional knowledges and comprehensions associated with ISO/IEC 17043, ISO 13528 and any given requirement of the standards, together with assessment techniques and procedure of academic and statistical management in an efficient manner. In fact, the workshop promoted competency of services related with proficiency testing provider in compliance with ISO/IEC 17043 to promote the country development.