OBJECTIVES: Considering The pivotal role of biochemical testing for the management of diabetes mellitus, we studied the current status of diabetes testing and reporting in three countries of the Asia-Pacific region. METHODS: A survey of 254 practicing pathology laboratories comprising of 40, 11 and 203 laboratories from Sri Lanka, Singapore and the Philippines was conducted under the auspices of the Asia-Pacific Federation for Clinical Biochemistry and Laboratory Medicine (APFCB) Working Group for Diabetes Testing Harmonization using Survey Monkey and Google Forms. RESULTS: The country response rate varied from 40% to 88%. A diagnostic threshold of 6.5% (48 mmol/mol) for HbA1c is reported by 51%, 22% and 90% of the participant laboratories in Sri Lanka, Singapore and the Philippines, respectively. All participants in Singapore and 86% of the laboratories in Philippines use NGSP-certified methods for HbA1c. Traceability to Certified Reference Materials for both glucose and HbA1c results was confirmed by 74% of Sri Lankan laboratories. For albuminuria testing, early morning spot urine albumin to creatinine ratio is recommended by 56%, 75% and 69% of the laboratories in Sri Lanka, Singapore and the Philippines, respectively, while 16%, 50% and 26% of the laboratories recommended 24-hour urine collection. CONCLUSION: There is a lack of harmonization in diabetes testing and reporting practices both across and even within the three countries surveyed. Scientific bodies or professional associations have an important role in harmonization of laboratory testing and reporting of results for the diagnosis and management of diabetes mellitus.