This article presents results of a study that seeks to understand how professional insertion of teachers at the secondary level in Quebec is affected by job insecurity, specifically from the perspective of beginning teachers. This qualitative research was based on semi-structured interviews with seven beginning secondary-school teachers who experienced their professional insertion in a context of job insecurity. The thematic analysis of our data clearly shows that this insecurity encumbers and decelerates the process of insertion and that it even affects the teachers’ work, professional development and the quality of teaching.