Professional development providers often struggle with how some teachers take up and internalise new instructional practices while others have difficulty implementing new ideas and strategies. Teacher personal characteristics account for only part of this differentiation in learning, and there are unanswered questions regarding how organisational conditions shape teacher learning in professional development (PD). To address these questions, we examined U.S. elementary teachers' learning and change in a science professional development project. We expected to find that, in addition to personal characteristics, teacher change would be differentiated by the type and number of constraints within the organisational environment. Instead, we found that teacher change was differentiated by teachers' ability to draw on areas of alignment and iterative learning as resources to resist anti-science and teacher-centred aspects of the organisational environment. These resources were generated through coherence between the PD, teacher pedagogical beliefs, and existing instructional routines, as well as observing student learning while trying out PD strategies.