The Swedish Supranational Reference Laboratory Network (SRLN) conducted its fifteenth external quality control round in 2025, assessing Level 3 laboratories that perform TB and drug-resistant TB antibiograms. In this assessment, the Tuberculosis and Pulmonary Research Department of the Pasteur Institute of Iran earned an excellent rating for its proficiency in determining mycobacterial sensitivity to first- and second-line drugs. By correctly analyzing all unknown samples, the department received an official external quality evaluation certificate from the World Health Organization’s SRLN in Sweden. This marks the seventh consecutive time the Tuberculosis and Pulmonary Research Department of the Pasteur Institute of Iran has achieved an excellent rating in this external proficiency-testing program.