The behavior of the infant with prenatal drug exposure (PDE) is different from a nonexposed infant, and it is a difference that changes the rules of interaction for the caregiver. Infants exposed to opiates such as heroin or methadone demonstrate very specific signs of neurobehavioral dysfunction as they go through classic withdrawal symptoms. Infants exposed to cocaine exhibit somewhat more subtle behavioral dysfunction, but many of the same symptoms are present. Infants with PDE have poor self-regulatory abilities and are either crying or sleeping. Motoric differences are evident in tone and movement. Autonomically, infants with PDE frequently have persistent tremors, startles, moderate tachypnea, and other signs. All of these signs of neurobehavioral dysfunction range from severe to moderate and often are still present throughout the first months of life. Reduction of stimuli is the key, as infants' dysfunctional behavior is the manifestation of overstimulation. Caregiving techniques include protection from light and noise, swaddling, gentle vertical rocking, soft quiet voice, quiet feedings, and careful phasing in of visual and auditory stimuli. (Contains 35 references.) (JDD)