The purpose of this study is to investigate the dynamic factors influencing willingness to communicate (WTC) in an English as a foreign language (EFL) classroom in Iran from an ecological perspective at a private institute over one semester. 6 students (2 males and 4 females) participated in the study allowing for intensive, individual-level microanalysis. The data was gathered through semi-structured interviews, classroom observations, and learning journals. A qualitative content analysis was applied to analyze the data through reading, coding and revising the codes analyzed by MAXQDA in light of Bronfenbrenner’s (1979, 1993) nested ecosystems model as an analytical framework. Six WTC factors within the microsystem of classroom ecology were indentified: cognitive factors, linguistic factors, and affective factors. In addition, factors at the meso-, exo-, and macrosystem, and their effect on classroom WTC were explained. The findings shed light on an ecological understanding of the dynamics of Iranian EFL students’ WTC in their language classroom. Also, the findings of this study have been compared with those of a previous study within the context of China Dynamic Emergent Patterns of L2 Willingness to Communicate Within the Ecology of Classroom.