Various forms of networks in education have been proposed by scholars, policymakers, and educational administrators as a strategy for school improvement. However, there are few empirical studies on the effect of interschool networks. We analyzed data from 76 elementary schools in a Midwestern state to examine the association between interschool relationships and student achievement by employing social network analysis and hierarchical linear modeling (HLM). After controlling for school and district demographic characteristics, we found that (a) schools that reported to have a stronger relationship with other schools had better math achievement, and more growth in reading achievement; (b) schools with reciprocal relationships had better math and reading achievement, and more growth in reading achievement; and (c) schools that connected to more influential schools in the network had better math and reading achievement, and more growth in reading achievement. We discussed the implications for research, policy, and practice.