Although family and friends typically provide informal care after a stroke, little is known about the relationship between social network structure and function and post stroke outcomes. As part of the Discharge Educational Strategies for Reduction of Vascular Events (DESERVE) trial, stroke/TIA patients were asked to identify up to 5 persons (“alters”) with whom they discuss important matters and provide information about each relationship. Network characteristics included number of alters, having an alter in the same household, having a family-only (vs. family and friend) network, frequency of contact with each alter, likelihood of discussing health concerns, relationship “closeness,” and educational level of each alter. Our outcome was the difference in systolic blood pressure (BP) between baseline and the 12 month follow-up (mmHg). We regressed BP change on our social network variables adjusting for trial arm, age, gender, race-ethnicity, and education. Of the 478 participants, 14% identified no alters, 58% identified 1 or 2 alters, and 28% identified 3-5 alters. Of those with at least one alter, 61% reported having an alter in the same household and 73% reported having a family-only network. Twenty-one percent of respondents reported talking to at least 3 alters at least several days per week, 22% reported having at least 3 alters whom they were very likely to discuss health concerns with, 23% reported having extremely or very close relationships with at least 3 alters, 14% of respondents reported having 3 or more alters with more than a high school education. In fully adjusted models, having 3-5 alters compared to none (beta = 10.86; p = 0.01), not having a family only network (beta = 6.11; p = 0.03), having at least 3 health matters network members compared to none (beta = 9.81; p = 0.01), having at least 3 extremely or very close relationships compared to none (beta = 9.18; p = 0.02), and having 3-5 network members with more than a high school education (beta = 11.77; p < 0.01) or 1-2 network members with more than a HS education (beta = 7.04; p = 0.04) compared to none was associated with greater mean BP reduction. Interventions that involve social networks may help reduce vascular risk and enhance secondary prevention efforts.