Objectives Participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) has been associated with lower breastfeeding initiation and duration. This study examines breastfeeding-related factors among WIC participants and nonparticipants that might explain these previous findings. Methods Respondents to the 2007 Infant Feeding Practices Study II who were income-eligible for WIC were categorized as follows: no WIC participation (No-WIC); prenatal participation and infant entry while ≥60 % breastfeeding (WIC BF-high); prenatal participation and infant entry while <60 % breastfeeding (WIC BF-low). Percent breastfeeding was the number of breast milk feeds divided by the total number of liquid feeds. Using propensity scores, we matched WIC BF-high respondents to No-WIC respondents on demographic and breastfeeding factors. We used logistic regression to estimate the impact of WIC participation on breastfeeding at 3 months postpartum in the matched sample. Within-WIC differences were explored. Results Of 743 income-eligible respondents, 293 never enrolled in WIC, 230 were categorized as WIC BF-high, and 220 as WIC BF-low. Compared to matched No-WIC respondents, WIC BF-high respondents had increased odds of breastfeeding at 3 months, though this difference was not statistically significant (OR 1.92; 95 % CI 0.95-3.67; p value 0.07). WIC BF-high respondents were more similar on breastfeeding-related characteristics to No-WIC respondents than to WIC BF-low respondents. Conclusions for Practice Accounting for prenatal breastfeeding intentions and attitudes, we find no negative association between WIC participation and breastfeeding at 3 months postpartum. This is in contrast to prior studies, and highlights the importance of understanding within-WIC differences.