Not all children begin kindergarten ready to learn. Young children who exhibit dysregulated or disruptive behavior in the classroom have fewer opportunities to learn and consequently achieve lower levels of academic skills (Arnold et al., 2006; Raver, Garner, & Smith-Donald, 2007). A growing body of literature has examined how children's temperament is related to their academic skills and classroom behaviors. Students with high maintenance or challenging temperaments are low in task persistence, and high in negative reactivity and motor activity, and have higher levels of behavior problems and lower levels of academic engagement (McClowry et al, 2010). These negative associations may be pronounced among low-income, urban children (Herman, Trotter, Reinke, & Ialongo, 2011). Teachers are often frustrated with students who have high maintenance temperaments. The combination of low task persistence, high negative reactivity and high motor activity results in the need for more teacher attention and can compromise teacher/student relationships (Rudasill & Rimm-Kaufman, 2009). Enhancing student-teacher relationship quality among children with high maintenance temperaments may a critical conduit for the effects of social-emotional learning (SEL) interventions for temperamentally difficult students. In this study the authors examined the efficacy of a temperament-based SEL intervention, "INSIGHTS into Children's Temperament" ("INSIGHTS"), in supporting the behaviors and academic engagement of children in urban, low-income schools during kindergarten and first grade with a focus on students with high maintenance temperament. Four tables and three figures are appended.