This paper explores the influence of women's social networks on child survival through a comparative investigation of two ethnic groups in Mali, West Africa. Data are drawn from a study of women's social networks and health conducted during the period 1996-97. Separate samples of 500 ever-married women aged 15-49 were surveyed at two geographically distinct sites representing Bamanan and Fulbe populations respectively. Consistent with known differences in economic risk, household structure, and cultural norms, descriptive analysis reveals a greater probability of child death among the Fulbe, and a larger mean size of total, material, practical and cognitive networks among the Bamanan. Cox regression models are used to examine the association between social network size, function and composition and the odds of child death (1-5 years). Among the various biological, household and community-level variables tested in the basic model, spacing exerts an expected negative effect on the odds of child death in both groups, while household SES predicts child survival only among Fulbe children. When variables representing the educational and psychosocial attributes of the mother are included, no effects are detected in either group. Controlling for these factors, the size of total, practical, cognitive and emotional networks are found to significantly increase the odds of child survival among the Fulbe only. Compositional variables, such as the extent to which natal kin, non-kin or husbands figure in a woman's network, nor the degree to which networks are located within household yield any significant results for the Fulbe. Among Bamanan women, however, the higher the proportion of network members living in the household, the lower the odds of child death. The paper concludes by discussing the methodological, conceptual and practical implications of these findings.