In this article the author describes a mixed-methods study of first-year urban teachers' social support networks. Social Network Analysis (SNA) data on the support networks of 24 first-year teachers provided a background context and framework for the case study analysis of 4 of the teachers. Findings of the analysis identified 2 important networks of support for the new teachers: "Intentional Professional Networks" and "Diverse Professional Allies." These findings have important implications for the ways in which administrators, policy makers, teacher-educators, and teachers can conceptualize and nurture teacher support networks and the interactions and relationships that influence teacher professional support. (Contains 6 tables, 5 figures and 4 footnotes.)