This study evaluated the Measure of Adult and Infant Soothing and Distress (MAISD) for examining infant, parent, and nurse behavior during infants’ immunizations. Videotapes of 62 infants, parents, and nurses during immunizations were coded. Concurrent validity and reliability for the MAISD were demonstrated. The scale revealed that infants displayed predominately distress, and adults exhibited primarily reassurance. Parents’ and nurses’ distractions were positively related to infants’ engaging in distraction, and parents’ and nurses’ reassurance was positively associated with infant distress. There appear to be avenues in which to intervene to teach parents and nurses how to best behave to help infants during their painful medical events.