This cross-sectional study examines Maryland’s women, infants, and children (WIC) breastfeeding initiation rates by program participation. The authors report on data regarding demographic and health characteristics and infant feeding practices for infants (n = 18 789) newly WIC-certified from January 1, 2007 to June 30, 2007. The authors compared self-reported, breastfeeding initiation rates for 3 groups: peer counselor (PC-treatment group) and two comparison groups, lactation consultant (LC), and standard care group (SCG). Reported breastfeeding initiation at certification was 55.4%. Multiple logistic regression analysis, controlling for relevant maternal and infant characteristics, showed that the odds of breastfeeding initiation were significantly greater among PC-exposed infants (OR [95% CI] 1.27 [1.18, 1.37]) compared to the reference group of SCG infants, but not significantly different between LC infants (1.04 [0.96, 1.14]) and the SCG. LC and SCG infants had similar odds of breastfeeding initiation. In the Maryland WIC program, breastfeeding initiation rates were positively associated with peer counseling. J Hum Lact. 25(4):435-443.