This Study on Economic Justification of Occupational Safety and Health (OSH) Implementation in the Construction Sector is a regional initiative in the Work Plan ASEAN Occupational Safety and Health Network (ASEAN-OSHNET) 2021-2025. It examined the implementation of OSH programmes in the construction sector and its economic gains across eight ASEAN Member States. The analysis showed that investments in occupational safety and/or health programmes in the construction workplace resulted in benefits that, from the economic perspective, are at least twice greater than the investment spent-- an affirmation that expenditures for OSH should be seen as an investment and not a cost.