In previous research, Luthar and Barkin (2012) found that across three different samples collected from three high-achieving schools, adolescents reported elevated rates of maladjustment behaviors, which include substance use, and internalizing and externalizing symptoms. Additionally, past research has also indicated that these maladjustment behaviors are related to parent relationships. A group of high-achieving adolescents that research has not yet focused on are those attending boarding schools, who may have higher-quality relationships with parents due to less daily strife. This study aimed to examine high-achieving adolescents across five samples from five high schools, two of which were boarding schools. This study hypothesized that the high-achieving adolescents attending both boarding schools would report lower rates of substance use, internalizing and externalizing symptoms, and lower rates of perceived parent criticism and expectations in comparison to those attending the day schools. Substance use, internalizing and externalizing symptoms, and parent relationships were measured using self-report measures that were completed by students attending these schools. Results showed that both boarding schools reported elevated rates of substance use in comparison to the three day schools and these rates measured above national norms. At the same time, both boarding schools reported lower rates of internalizing and externalizing symptoms when compared to rates reported by the day school students. This study also found that there were differences among parent relationship measures, such as criticism and expectations, among all school samples. Results of this study also showed that aspects of parent relationship, such as parent knowledge, were associated with rates of substance use among all school samples. In summary, boarding school students showed elevated substance use, similar parental relationship quality, and lower mental health symptoms compared to day school students. For all students, some aspects of the parental relationship were related to levels of substance use.