OBJECTIVES: To quantitatively benchmark Health Technology Assessment (HTA) agencies for attributes of transparency. METHODS: We developed a Likert scale (0-5, higher score>best practice/ease of accession) to benchmark HTA agencies on standards for submission. The scale comprises 77 questions grouped into 18 principles (P1-P18) and 6 domains - transparency, process, technical, equity, speed, and implementation. To represent the importance of critical dimensions of HTA process, principles were weighted differentially. Here we present weighted analyses of the transparency domain for national agencies from 6 countries: Australia, China, Japan, South Korea, Taiwan, and Thailand. RESULTS: The principles under transparency (max possible score and weightage in parenthesis) were: P1- HTAs are unbiased, rigorous and transparent (10.5; 10.5%); P4 - HTAs incorporate appropriate methods depending on its goal (8.8; 9.4%); P12 - HTAs are transparent in pricing, reimbursement and market access policies (4.1; 3.5%); P14 - HTAs are transparent on recommendations around economic evaluation (2.9; 7.0%). The overall weighted score for the transparency domain was highest for Australia (24.1), followed by South Korea (23.1), Japan (16.8), Taiwan (16.0), Thailand (14.0), and China (9.6). A higher score for Australia and South Korea was primarily driven by higher scores in P1 (9.5 and 8.9 respectively) and P4 (8.8 each). The key HTA dimensions driving higher transparency of agencies like Australia and South Korea are transparent decision making, clear process for sponsor and unbiased & independent HTA independent from health system CONCLUSIONS: The factors driving higher transparency - a key attribute of HTA maturity - are providing pre-submission consultation, a set rare diseases/orphan drug process, involvement of multi-level stakeholders, transparent pricing process, and a clear correlation between the goal of HTA agencies and its process. Evolving HTA agencies should consider adding greater transparency in submission process, stakeholder engagement, and evaluation method to evolve rapidly through the HTA maturity curve.