Prenatal and postpartum anxiety may impair maternal functioning and disrupt mother–infant behaviors including breastfeeding. The objective of this narrative review is to examine the association between maternal anxiety from pregnancy to 12 mo postpartum and breastfeeding initiation, duration, and exclusivity. Using a combination of Medical Subject Headings terms and text words, relevant studies were identified through PubMed and PsycINFO. Studies that were conducted in high-income countries, assessed anxiety during gestation and/or postpartum through a standardized measure, and evaluated the impact of anxiety on any of the primary outcomes were included. Sixteen studies met the eligibility criteria although they varied greatly in methodological rigor. A negative association between postpartum anxiety and breastfeeding initiation, duration, and exclusivity was suggested. No associations were found between prenatal anxiety and breastfeeding initiation or exclusivity. Evidence is mixed regarding the association between prenatal anxiety and breastfeeding duration. All studies included in the review were of low or very low quality. Although there was consistency in the association between maternal anxiety and breastfeeding outcomes in the included studies, future studies with greater methodological rigor are needed to determine the extent of the relation between prenatal and/or postpartum anxiety and breastfeeding outcomes.