This study is the first in Australia to investigate teachers’ knowledge, attitude and behaviour towards supporting young people in their class who have a parent in prison. Numbers of young Australian people affected by parental imprisonment has significantly increased over the past decade. In Australia, it is estimated that 145,000 young people under 16 years of age (almost 5% of all children) have had a parent imprisoned, rising up to 20% of under 16 year olds from Aboriginal communities. Young people with a parent in prison are vulnerable given they are six times more likely to end up in prison themselves and 40% more likely to dropout of school than their peers. Early intervention to interrupt the cycle of intergenerational offending is critical. Outside of the family, schools are the next most significant developmental context for young people. They provide a safety net and assist in protecting young people from circumstances that impact their learning, development and wellbeing. Given the significance of school as a setting for building protective factors, teachers can play an instrumental role in supporting the development of these young people. Recent research reveals however, that teachers are unaware of the research on how best to support young people with a parent in prison and currently receive no targeted pre-service or in-service training. Many schools have no policies in place to support these vulnerable young people. The first step to inform teacher training programs on supporting young people with a parent in prison is to develop an understanding of teachers’ current knowledge, attitude and behaviour. To achieve this, a new instrument has been developed and will be psychometrically tested to confirm its reliability and validity. The new instrument will be a valuable tool to examine how and what teacher factors change over time with the introduction of future evidence-based teacher training programs designed to facilitate teachers to support young people in schools who have a parent in prison.