This study examines the relationship between opportunity-to-learn (OTL) at home and students' attainment of science proficiency. The data set used was the 2006 PISA science US national sample. Data mining was used to create patterns of association between home OTL variables and student attainment of science proficiency. It was found that students who failed to reach science proficiency are characterized by having fewer than 100 books at home; these students are also found to take out-of-school individual or group lessons with their teachers or with other teachers. On the other hands, students who reached science proficiency are characterized by having more than 100 books at home, not taking any out-of-school lessons, and having a highest parent level of graduate education. In addition to the above common characteristics, other home characteristics (e.g. computer and internet at home and language spoke at home) are also identified in profiles of students who have reached science proficiency. We explain the above findings in terms of current social-cultural theories. We finally discuss implications of the above findings for future studies and for improving science education policy and practice.