In this article, the authors explore the importance of interpersonal relationships for facilitating Latino/a students' academic success, focusing on the way that dynamic notions of culture enhance their understanding of these crucial relationships. The authors discuss two types of relationships that support student success: (1) relationships with adults in schools; and (2) relationships with peers, family, and community members. Supportive social relationships among friends, adults, and families both in and out of school provide young Latinos/as with the grounding, knowledge and impetus to navigate the difficult waters of a highly competitive and often intolerant American society. Social scientists commonly categorize such helpful relationships as social capital. The authors argue, however, that "culture"--when understood as the meaningful practices people engage in every day--lays the foundation for the development of constructive relationships and thus for the formation of social capital useful for educational achievement. An educational environment that promotes the cultural practices of Latino/a students engenders the interpersonal relationships among students, school staff, and parents that can lead to higher achievement. Here, the authors describe how social capital facilitates educational achievement, focusing on relationships as a form of social capital. The authors then describe how a comprehensive understanding of "culture" is critical for understanding how Latino/a students develop and access social resources.