By analyzing the prior knowledge of African American students, this study explored the relationship between cultural orientation of literature and reading comprehension to determine its effect on low, mid, and high level readers. Over one hundred 8th grade students from four different public schools read short stories from three different cultural orientations. Their reading comprehension performance was analyzed to determine the role that culturally-bound prior knowledge plays in the comprehension process for low, medium, and high performing students. To measure the effects of cultural orientation of texts, prior achievement, and prior knowledge on the students' reading comprehension performance, the study utilized the Rasch model and ANOVA. The data revealed a high level of culturally-bound prior knowledge supports students' reading comprehension. Cultural support was especially important to readers at the mid range achievement level. (Contains 7 tables and 2 figures.)