The objectives of this study were two-fold: to present an indepth and systematic view of the day-to-day experiences of a group of beginning primary school teachers (N=38) during their first year of teaching, and, to derive from this, a theory which would elaborate and clarify the process of socialisation for these teachers. Throughout the 1979 school year, data was collected from this sample of teachers, and from their Principals, Senior Teachers, colleagues and Inspectors, using a selection of case study research techniques (e.g., interviews, diary accounts, questionnaires) in conjunction with a strategy for theory construction known as “grounded theory”. The outcome of using these two approaches in tandem was the development of a low level theory about the socialisation of these beginning teachers grounded in data relating to their day-to-day experiences during the first year of teaching. This grounded theory was comprised of seven major categories: Pupil-Teacher Influences, Parent-Teacher Interaction, The Role of the Principal, Guidance from the Senior Teacher, Associating with Colleagues, Inspectorial Visits, and Management and Organisation Patterns. These seven categories represented the over-riding factors, which were able to be identified, in the process of socialisation for this sample of Year One teachers. Within each of these categories, a set of suggestive, generalisable propositions about the socialising situations and influences which may be experienced by first year primary school teachers was formulated. The uses and implications of this grounded theory are wide ranging, and in the concluding sections of this report these are discussed. It is suggested, for instance, that the theory may be of use to at least four groups of people: school personnel, such as those who have a direct interest in the welfare of beginning teachers (e.g., Principals, Senior Teachers and Inspectors); beginning teachers and students in training; teacher educators; and, researchers interested in studying first year teachers and the teacher socialisation process. As well, the grounded theory has implications for the professional development of Year One teachers. For example, it is recommended, on the basis of this study, that teacher training institutions should endeavour to increase the level of awareness student teachers have about the first year of teaching, and that provisions should be made for a formalised preservice orientation programme and on-the-job training for first year teachers. Another implication arising from the grounded theory is that little support can be given to the lock-step, input/output models and theories of teacher socialisation which are prevalent in the literature. Finally, in the area of methodology, especially in relation to doing fieldwork in schools and in using the grounded theory strategy, this study has had several pay-offs. In particular, some of the dilemmas and pitfalls associated with data collection, the fieldworker being a participant, the influence of researcher bias in developing theory, and the mechanics of data analysis, have been highlighted.