ABSTRACT. This study was designed to determine the immediate effects of waterbed flotation on approach and avoidance movements in premature infants. Twenty-two premature infants free of major medical complications were randomly assigned to experimental (n = 11) or control (n = 11) groups. After each of five consecutive gavage feedings, each infant in the experimental group was placed for 30 minutes on a Medpro Neo-Float Neonatal Flotation System with oscillating dual frequency rhythmic wave stimulator. Control group infants were placed on standard isolette mattresses. Differences between groups were highly significant on five of six behaviors observed, with the occurrence of hand-to-mouth greater and the frequencies of grimace, startle, trunkal arch, and salute behaviors less in the experimental group than in the control group. No significant differences were noted on finger splaying. These results have possible implications both for the routine use of waterbeds in intensive care nurseries and for the specialized use of waterbeds in infant stimulation programs.