This paper explores how trust in teacher professional judgement has been reconstituted through the globalised trends of performative accountability and increasing data-driven logics. The article draws upon empirical research from a larger study in two geographically and contextually bound Queensland public schools from interviews with X Prep to Year 9 teachers and X school leaders, observations of teacher preparation days, classroom observations and staff professional learning communities (PLCs). Drawing upon Kemmis et al.’s (2014) concept of Practice Architectures, the paper focuses attention upon the socio-political, material and discursive conditions inscribed in how data are currently understood and deployed, and how these conditions constrain trust in teachers, devaluing teacher’s own professional judgement. Specifically, we flag how the conditions and practices that constrained ‘trust’ were manifest in mistrust amongst parents and a subsequent need to evidence decision-making on the basis of ‘hard data’, and pressures to ensure teachers generated and collected such data on an ongoing basis to substantiate their claims about student learning. Through uncovering the particular ‘sayings,’ ‘doings’ and ‘relatings’ in conjunction with the cultural-discursive, material-economic and socio- political arrangements that drove these practices (Kemmis et al., 2014), we can reveal the specificity and varied ways in which current data and assessment policies and procedures are actually eroding trust in teachers and their professional judgement in relation to student learning and achievement.