This study presents the development and validation process of an instrument to measure early career teachers’ work socialization. A total of 1487 teachers of different levels of education participated is this study. The theoretical foundations as well as the exploratory and confirmatory factorial analyses highlight four dimensions of work socialization: socialization into the workgroup, into the micro-political climate, into the teaching tasks and into the organization. According to commonly used validity process standards, the proposed instrument demonstrates high validity evidences. This contribution offers support for the adaptation of a holistic approach towards teacher induction that goes beyond classroom work tasks.