This paper examines the usage of the term “environment” in Frederick Kiesler’s discourses from the 1920s to the 1930s, during the early stages of his career. By doing so, it sheds light on the theoretical development and background leading up to his seminal 1939 essay “On Correalism and Biotechnique.” This study categorizes Kiesler’s usage of the term “environment” into three stages: (1) its use in theatrical discourses during the 1920s, (2) its expansion into architectural discourses in the early 1930s, and (3) the establishment and complication of the concept in the late 1930s, thereby revealing its consistency and variations.