The specific problem this research studied is the relationship between principal instructional leadership behaviors and student achievement in Nigeria. Eight of the often cited principal instructional leadership behaviors were selected for study. They are: set goals; set expectation; provide resources, human/material; manage/coordinate curriculum and instruction; establish school climate; promote staff professional development; and monitor student progress. The purpose of this study was to determine the relationship between the eight selected principal instructional leadership behaviors and student achievement in Nigeria. Using the stratified random sampling technique, a sample of 400 teachers, and 40 principals was selected from 40 secondary schools in Edo State. Two questionnaires were developed to gather data for the study. Data collected were analyzed using descriptive statistics, and pictorial presentation. The descriptive demographic variables gender, age, experience, and education, were used to describe the data gathered. The independent and dependent variables were subjected to inferential statistics using the Pearson product – moment correlation coefficient technique. Eight null hypotheses were tested to determine the statistically significant relationship between the eight independent variables and the dependent variable. The level of significance chosen was .05. The primary findings indicated that there are no statistically significant relationship between any of the eight independent variables and the dependent variable. Therefore, it could be concluded that there are other variables that are related to student achievement in Nigeria, though the eight independent variables could enhance it. Student intrinsic motivation, discriminating synthesis of old and new values, and a return to the Nigerian tradition are variables offered as those that are related to student achievement in Nigeria. Of all these variables, student intrinsic motivation seems to be the recurring variable that is most related to it. Nine main recommendations were made to the Nigerian students, scholars, school system, and society.