While prior research has examined relationships between grades and test scores (e.g., Brennan, Kim, Wenz-Gross & Siperstein, 2001; Ross & Kostuch, 2011), this study examined the influence of students' gender on the relationship between grades, what teacher "expected" students to score on end-of-grade or end-of-course (EOG/EOC) exams, and what students actually scored on EOGs/EOCs. Discrepancies between achievement measures showed that while the relationship between grades and test scores followed similar patterns to those found in prior research (Brennan et al., 2001; Martinez, Stecher, & Borko, 2009), relationships between expected EOG/EOC achievement levels, actual EOG/EOC achievement levels, and performance grades indicated that teachers tended to underestimate the degree to which students' performance grades differed from their actual EOG/EOC scores. This study used 80,247 student records from reading, math, and science courses spanning three years covering grade levels 3 through 12 from a school district in western North Carolina. The following information was collected for each student: the performance grade the teacher anticipated assigning to the student (AntGrd), the expected achievement level for each student on the North Carolina (EOG) or End-of-Course (EOC) assessment (ExpLvl), and the actual achievement level each student scored on his or her EOG/EOC assessment (ActLvl).