In universities, development as a teacher may be contradicted with developing as a researcher. Most previous studies have investigated pedagogical development merely as a result of pedagogical training and ignored the dual teacher-researcher identity. This study examines what kind of meaningful experiences are perceived to have triggered and influenced the process of developing as a teacher in the fields of science and technology. The data were gathered by interviewing 10 academics who had participated in a pedagogical training offered by a Finnish technical university between 1999 and 2009. Based on a narrative analysis utilizing dimensions of transformative learning, the results highlight the influence of the working environment and experiences, and imply that teacher development process in the fields of science and technology can be better understood in terms of becoming a teacher, rather than as a continual, conscious development process. The resulting teacher-researcher identity provides a basis for pedagogical development.