Teacher leadership has gained increasing recognition worldwide as a crucial component of educational reform and improvement efforts. As a concept, it is not new; its evolution spans several decades, yet there is still dissonance around it. This is especially true in the Greek educational scene, where teacher leadership research is limited and fragmented. This study seeks to address this gap by exploring the factors contributing to and impeding the evolution of teachers' leadership in Greek schools. More specifically, we were interested in knowing what Greek in-service teachers with informal leadership positions think about teacher leadership prospects within the Greek educational context, what conditions they think enhance or impede teacher leadership development in Greek schools, and what opportunities they think there are for developing teacher leaders. A sample of 12 experienced in-service teacher leaders from different educational specializations and geographical regions in Greece participated in the study. A grounded theory methodology was employed to analyze the data collected through focus group interviews with experienced in-service teachers. The findings of this study include references to personal and interpersonal challenges that create barriers to the evolution of teachers as leaders in Greek schools, as well as administrative impediments and a lack of support for prospective teacher leaders. The participants reported opportunities within the Greek educational system for teachers to evolve as leaders through targeted and consistent professional development programs and school improvement initiatives. Implications for research and practice are drawn from these findings.