Empirical research into translation processes using think aloud protocols initially described the processes of naive translators, language students who were not studying translation. It then moved to a focus on novice translators, i.e., translation students, and finally investigated professional translators. Some of these latter studies showed that not all professional translators produced high-quality products, raising the question of how to define the notion of “professional translator.” Recent studies of translation expertise have brought a new perspective to the question of professionalism and expertise in translation. This paper looks at some of the different ways of defining the two concepts, and some early findings in process studies are reinterpreted from the point of view of more recent expertise research.