The purpose of this research is to develop a designer’s checklist encompassing the various categories of healthcare facilities (HCFs). This checklist is based on the research available about the elements/factors of the healing environment. An evidence-based design was used to conduct this study. Online database searches on Google Scholar, JSTOR, Scopus, and PubMed using various keywords, such as healing environment, evidence-based design, patient safety, infection, medical errors, patient falls, stress reduction, social support, single bedroom, views of nature, daylighting, music therapy, and noise levels in a healthcare setting were used for data collection. The collected data was analyzed based on the level of evidence and sorted accordingly for the development of three types of a designer’s checklist encompassing optimal healing environments. All the elements/ factors of environmental design were coded according to their level of evidence and were sorted into three categories: 1) Fair level of evidence (F) comprising expert opinions, case series, and case reports, 2) Good level of evidence (G) comprising cohort studies and case-control studies, and 3) Excellent level of evidence (E) comprising randomized controlled trials and systematic reviews. To create an optimal healing environment, this study proposes three different levels of healing environments corresponding with the three levels of HCFs as follows: 1)healing environment Level-I for tertiary HCFs includes elements/ factors of environmental design with E, G, and F levels of evidence, 2)healing environment Level-II for secondary HCFs includes elements/ factors of environmental design with E and G levels of evidence, and 3)healing environment Level-III for primary HCFs includes elements/ factors of environmental design with E level of evidence. This study makes the designing and renovation of HCFs to create an optimal healing environment easily measurable and achievable. Keywords: Checklist, healing environment, healthcare facilities (HCFs), hospital design, measurement