The communicative language teaching approach that informs many school modern foreign language programmes has been realised in different ways as theorists and practitioners have sought to identify the most effective combinations of instruction and use [Mitchell, R. 2000. Applied linguistics and evidence-based classroom practice: the case of foreign language grammar pedagogy. "Applied Linguistics" 21, no. 3: 281-303]. Task-based language teaching (TBLT) is one such realisation. TBLT's learner-centred and experiential emphasis on use contrasts with more directly instructional models such as presentation-practice-production (PPP). Given the prevalence of practices such as PPP, the effective realisation of TBLT is challenging. This article presents findings from a small-scale study among practising teachers (N = 7) three years after an initial teacher education focus on TBLT. Semi-structured interviews explored how the teachers understood and enacted task-based principles in their classrooms; their perceptions of the barriers to successful implementation; and their responses to perceived barriers. Findings suggest that TBLT principles can be successfully enacted by teachers who are open to the innovation, but that theoretical, practical and contextual constraints limit that enactment. Implications for sustaining innovative practices are presented.