Abstract: Background: Analysis of differences in the incidence and duration of breastfeeding across countries may provide information about practices that encourage breastfeeding. This comparative review examines variation in the incidence and duration of breastfeeding for term infants that has been reported in studies from Canada, the United States, Europe, and Australia. Methods: Searches were conducted in PubMed, MEDLINE (from 1966), CINHAL (from 1982), and the Cochrane Database of Systematic Reviews. Studies were limited to nonexperimental and observational research that addressed term infants (>37 weeks gestational age), performed in developed countries, written in the English language, and published since 1990. Additional studies were located from reference lists of meta-analyses, systematic reviews, and previous articles. All studies that met study criteria were included in the review, regardless of the quality of methodology. Results: Although studies had methodological limitations that precluded conducting a formal systematic review or meta-analysis, this comparative review revealed consistent differences among countries. For example, Europe and Australia reported a higher initiation and duration of breastfeeding term infants compared with Canada and the United States. Conclusions: Studies that examined reasons for a higher incidence and duration of breastfeeding term infants consistently document that women who initiate and continue to breastfeed are older, married, better educated, and have higher family incomes than women who do not breastfeed.