Research for the past decade has examined academic performance gaps among students from the perspective of sex, race and ethnicity groups, and low socio-economic status. Across those studies school attendance has been identified as a primary correlate with academic success. I used a descriptive non-experimental design to investigate the relationship of student academic outcomes (i.e., GPA, credits earned toward graduation) among student groups (i.e., sex, race, and special education status) on attendance type of unexcused or excused absences. This study included two cohorts of 9th grade high school students (n = 2,262) from the Eugene 4J School District during the 2013 to 2016 school year. I calculated Chi-square tests, Independent t-tests, and Pearson’s correlation coefficient to examine the relationship of attendance with student academic outcomes for GPA and credits earned toward graduation and to further compare attendance type (i.e., unexcused or excused absences) among student groups. Findings indicated statistically significant differences for unexcused and excused absences and for GPA and credits earned by specific demographic subgroups – males v. females, white v. minority, special education v. not special education. There were also statistically significant correlations for GPA and credits earned based on unexcused and excused absences among demographic subgroups. In addition, there were statistically significant differences by academic and attendance variables for students who remained in comparison to students who left Eugene 4J.