Postpartum smoking contributes to child health problems and is a barrier to breastfeeding, which promotes child health. There is a risk of postpartum smoking relapse for smokers and they are less likely to breastfeed. Understanding of smoking–breastfeeding associations must be improved. Enhancing smoking cessation advice simultaneously with breastfeeding counseling could increase smoking abstinence and breastfeeding rates. A low income sample of 31 volunteer maternal smokers and ex-smokers were recruited for this pilot intervention in an urban hospital's postpartum unit. Following pre-intervention interview, participants received either smoking relapse prevention plus breastfeeding counseling, or smoking relapse prevention only counseling. At one-month follow-up, we hypothesized that breastfeeding duration would positively relate to 7-day point prevalence abstinence rates and days to relapse and explored prenatal care and pregnancy smoking behavior associations with postpartum smoking and breastfeeding. Of the mothers, 75% completed follow-up. Days to relapse was related to duration of breastfeeding (r = 0.92, p = 0.08); however, counseling group differences in one-month smoking status were not significant. Earlier prenatal care initiation was associated with smoking abstinences at one month postpartum (χ2 = 4.87, p ≤ 0.05). Early prenatal care and breastfeeding is associated with postpartum smoking abstinence.