A survey of infant feeding practices among the coastal Guatemalan ladinos illustrates the need for identification of influential local beliefs and customs on breast or bottle feeding. The factors in the trend toward bottle feeding are complex, and include: convenience for working mothers; media advertising; the existence of relatively cheap breast milk substitutes; and numerous cultural beliefs associating breast milk with infant illnesses. Colostrum is believed to be harmful to the newborn; rags soaked in sweet syrup are offered instead. Sudden withdrawal of the nipple is believed to cause a vacuum in the baby's head, resulting in a sunken fontanel. Many nutritious foods are avoided because they are suspected causes of diarrhea. Since these factors have not become associated with bottle feeding, many women are ready to adopt bottle feeding. If breast feeding is to be encouraged, local customs must be considered by health personnel. (cj)