Scholars suggest that when teachers retain, reuse, revise, remix, and redistribute Open Educational Resources (OER), the process of OER-enabled Pedagogy (OEP), they not only gain high-quality, digital teaching materials, but they also transform their teaching (Wiley, et al., 2017). Nonetheless, OEP is not an automatic outcome of using OER, rather it is dependent upon practicing key competencies through strategic professional development (PD). This paper reports a mixed-methods case study that contemplates the impacts of PD on OEP with five secondary education teachers, an under-investigated population. The findings reveal that small-scale PD can be successful in growing knowledge about OER, but that OEP is only catalyzed when teachers are required to reuse the OER in their classroom. Furthermore, small-scale PD cannot combat barriers like digital and information literacy that impede engagement in OEP efficiently and this may ultimately prohibit its sustainability in secondary contexts.