Human infants less than 4 months of age ingested water and moderate concentrations of sodium chloride solution (0.10-0.20 M) in equal amounts. In contrast, infants 4-24 months of age exhibited heightened acceptance of saline solution relative to water. Such a developmental change in salt acceptability is consistent with a hypothesis of postnatal maturation of peripheral and/or central structures underlying this response. Children 31-60 months of age tended to reject saline solution relative to water. This change may in part reflect the effects of experience.