The primary purpose of the present study was to determine if a relationship existed between perceived instructional leadership behaviors of high school principals and student academic achievement. A total of 124 principals and 410 teachers representing 75 high school campuses completed the School Leadership Behaviors Survey (SLBS), an instrument derived from 21 principal instructional leadership behaviors purported to relate to student achievement (Waters et al., 2003). Correlation analyses were used to analyze relationships between principals' and teachers' perceptions of the 21 instructional leadership behaviors and student achievement as indicated by campus average achievement scale scores in mathematics, social studies, science, reading, and English language arts. In addition, correlation analysis was used to examine the relationship between the congruence of principals' and teachers' perceptions and student achievement. The study revealed that principals' and teachers' perceptions of instructional leadership behaviors, and congruence between perceptions, were not related to student achievement (average effect size). However, when each of the 21 instructional leadership behaviors was examined individually, statistically significant relationships were found. Positive correlations were found between student achievement and 3 of the 21 instructional leadership behaviors: (a) flexibility, (b) input, and (c) outreach as self-perceived by principals. In addition, principals' perceptions on one instructional leadership behavior (discipline) produced a negative correlation with student achievement. Teachers' perceptions of the principals' instructional leadership behaviors positively correlated to student achievement on 2 of the 21 instructional leadership behaviors: (a) ideals/beliefs and (b) order. When differences in principals' and teachers' perceptions were examined, 12 of the 21 instructional leadership behaviors produced a negative correlation to student achievement: (a) communication, (b) contingent rewards, (c) culture, (d) discipline, (e) flexibility, (f) focus, (g) ideals/beliefs, (h) input, (i) optimizer, (j) order, (k) resources, and (l) situational awareness. These results indicated that, as principals' and teachers' perceptions of the instructional leadership behaviors were closer together (high congruency), student achievement increased. The results of the study confirmed that certain instructional leadership behaviors of the principals related to student achievement. The findings concerning the congruence between principals' and teachers' perceptions have encouraging potential in explaining student achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]