Academic underachievement in young adolescents has been a concern for teachers, schools and systems for some time. In Australian schools, curriculum reforms and middle years programs have been implemented to improve the educational outcomes of young adolescents, and address underachievement, with limited continuity and consistency. This study used a mixed methods approach within a collective case study to investigate characteristics and practices of secondary school teachers when identifying and dealing with academic underachievers in Years 7 and 8. Findings revealed that teachers identified the following as primary indicators of an academic underachiever: literacy and numeracy barriers; absences; family background factors; and, a lack of engagement, participation and confidence in learning. These teachers implemented specific practices to help address student underachievement including attempting to improve pedagogical relationships, collaboration with colleagues, aides and parents, and adjusting and modifying curriculum. The findings showed that these practices were not consistently informed by learner-centred or middle years educational models, but tended to be practical responses provided to assist underachieving students participate in learning activities and assessment and to meet age and stage curriculum standards. Teachers believed their practices were negatively influenced and limited by lack of time, system support and resources. While recognising that academic underachievers had complex needs, the practices teachers employed in the classroom were generally remedial and did not necessarily encourage the development of learner confidence in their students.