Differentiated Instruction (DI) continues to be a framework adopted within K-12 settings as it supports planning for the needs of diverse groups of students. However the research base exploring the implementation of DI is limited. The current study explores the relationships between individual and contextual variables on teachers' use of DI practices drawing upon data from a survey (N = 4875) and focus groups (N = 46). Results indicate that beliefs, self-efficacy and organisational support were significantly related to teachers' DI practice. Teachers described varied understandings, misconceptions and beliefs about DI. Research and practice implications are discussed.