The quality control of testing and inspection laboratories operated in Korea, the United States, and Canada was compared. The basic framework of on-site evaluation operated by each country was similar in terms of evaluation procedure, document evaluation, issuance of verification certificate, and follow-up management. For conducting on-site evaluation and granting the certificate, the preparation materials and evaluation processes are subdivided in Korea, while the dates of granting the certificate are restricted to four times a year in the United States. After receiving accreditation as a testing/inspection laboratories for the first time in Canada, follow-up management is divided into re-evaluation, verification evaluation, and monitoring evaluation.