The primary objectives of this research were to explore achievement pattern differences and the influence of family factors on the achievement patterns of Afro-Caribbean and African American students within the United States (U.S.). The study utilized two research designs; a causal-comparative and a correlational design. A student family background questionnaire was distributed to a sample of 87 high school students who were either Afro-Caribbean or African American. Additionally, students' chemistry quarterly test scores were obtained and results showed that Afro-Caribbean students outperformed African Americans. The difference was statistically significant (t = 2.43, p less than 0.05). Results also suggested that there were a few significant differences in the Afro-Caribbean and African American students' family background factors. (Contains 4 tables.)