In the analogy between design and language, two main categories are often distinguishable, that is, elements and principles. Elements can be considered as words in the design language and accordingly the principles would be the grammar or rules for employing these elements. The subsets of principles and elements in different fields of design are oftentimes inconsistent with each other and may vary according to the characteristics of that particular field. The roots of the formation and definition of many notions about the principles and elements of design can be found in applied arts or visual arts other than interior architecture, and hence they do not have a comprehensive and accurate definition tailored to the requirements of interior design. The purpose of this research was to discover and examine the design elements involved in interior design and the ways of achieving a precise and comprehensive definition of them by recognizing the design elements in interior architecture. As such, this study sought to define and refine the design elements in interior architecture and hence employed a methodical process to find a list of design elements in interior architecture, providing acceptable and agreed-upon definitions of design elements in interior architecture in the aftermath. Knowing the design elements and their examples in interior architecture are heavily involved in reading and describing an interior space. This qualitative-research research has accordingly sought to collect information from library sources and archives to offer initial definitions on design elements to be reviewed by experts in the field of interior architecture. Their views were then applied to the initial definitions in the form of the two-stage Delphi method to attain agreed-upon definitions for the Delphi panel. As a result of this research, various items were added to the previous body of design elements in interior architecture, and hence the list was revised with more precise definitions of design elements in the field of interior architecture, including point, line, surface, shape, form, mass, texture, role, color, light, space, time, smell and sound were obtained.