Rational Drug Use (RDU) has been set to be a strategic policy since the first issue of the National Drug Information. In the fiscal year of 2560 B.E., the Ministry of Public Health defined RDU and antimicrobial resistance management were projects under the National Strategy (2018-2037) regarding public health, and announced that all hospitals were RDU hospitals. RDU hospitals were evaluated with 18 hospital indicators according to the guidelines of service plan development. Some researches reflected limitations and obstacles of the RDU hospital indicators administration; however, this research was undertaken. The objective of this study was to review and develop rational drug use indicators for healthcare facilities. A cross-sectional, convergent mixed methods design was conducted between May 10, 2021 and November 9, 2022. Quantitative research was carried out with an online survey and analyzed with descriptive statistics. Qualitative research included documentary research, semi-structured in-depth interview, field study with group discussion, and modified Delphi technique, and analyzed data with thematic analyses. Also, a public hearing inquiry was held in representatives or experts of hospitals, professional organizations, and policy makers. Research population were all public healthcare facilities in primary, secondary, and tertiary care. Samples were selected from multi-stage sampling in both Bangkok and upcountry. In research summary, all hospital indicators should be kept, although some indicators were suggested to be terminated. The reason was to be the national database of all healthcare facilities until there will be better quality, efficient, and effective indicators. At present, RDU indicators will be divided into three categories. First, the Monitor (M) category included indicators Item no. 2 and 5. The Amendment (A) category were indicators Item no. 3, 4, 8 and 11. The Existence (E) category, lastly, were indicators Item no. 1, 6-7, 9-10, และ 12-18. Further studies will be needed to develop Thailand to be a RDU country. For examples, researches related to 1) spatial environment, 2) non-communicable diseases, 3) drug labelling and information, 4) RDU curriculum, 5) political research, 6) drug use in upcountry, grocery store or community pharmacy, 7) drug use in food chain cycle, and 8) information and exchange system.