It is increasingly recognised that language teachers' self-efficacy (LTSE) beliefs, i.e. their beliefs in their abilities to fulfil specific language teaching-related tasks that support learning, play a crucial role in filtering the way that their knowledge is transformed into action. Nevertheless, despite their importance, these beliefs remain under-researched in specific domains of language teachers' work, including grammar instruction. Set in a Turkish university foundation programme context, this study addressed the gap, drawing on research instruments that elicited LTSE beliefs for grammar instruction, together with self-reported classroom practices and self-perceived language proficiency, while grammatical awareness was assessed. Factor analysis led to the identification of three different types of grammar teachers. Calibrating individuals onto the three factors and making use of qualitative data helped the researchers to identify positive relationships between higher LTSE beliefs, greater levels of grammatical awareness and self-reported, discovery learning, grammar instruction practices in some teachers. Implications for in-service language teacher education are discussed.