This quantitative study investigated whether a relationship existed between principal's instructional leadership behavior and college readiness as measured by ACT scores in Catholic and private schools in south Louisiana. The study surveyed both teacher and principal perceptions of principal instructional leadership behaviors through the Principal Instructional Management Rating Scale (PIMRS). This survey was sent to participating school principals to complete in south Louisiana who then sent the survey out to their faculty. The data were collected and analyzed using descriptive statistics, a dependent t-test, and logistic regression. The results indicated that female principals felt they actively participated in instructional leadership more often than their male counterparts did. Teachers also perceived their female principals actively participated in instructional leadership more often than the teachers of male principals did. Finally, the research indicated that Catholic and private schools with male principals were 76% less likely to have ACT scores that were higher than the national average of ACT scores of private schools. This study may offer insight to educational leaders on how instructional leadership may relate to college readiness as demonstrated by ACT scores.