The process of teaching is complex and multidimensional. Teaching behaviors and actions are shaped by numerous cognitive decisions made by the teacher before, during, and after instruction. This article examines teacher cognition across the broad field of education and, more specifically, physical education in teacher planning, instruction, and reflection. To date, research has largely examined the areas of planning, instruction, and reflection separately and often in controlled settings. It is suggested that future researchers examining teachers' thoughts and actions employ methodologies, such as case study, that examine the three processes holistically and in the natural teaching environment, thereby linking actual behaviors with the cognitive processes that produced them.