The purpose of this study was to investigate the effects of audiotaped lullabies on physiological and behavioral distress and perceived pain among children during routine immunization. An experimental design was used to study 99 healthy children ages 3 to 6 years. Half the children received the musical intervention during the immunizations, while the other half did not. Groups were assessed during five phases: baseline, preimmunizations, during the immunization, after Band-Aid application, and 2 min after phase 4. Physiological variables (heart rate, blood pressure) were obtained in phases 1, 4, and 5. Behavioral distress was measured using the Observational Scale of Behavioral Distress during phases 1, 2, 3, and 4. Pain perception was measured using the Oucher in phases 1 and 4. No significant differences were found between experimental and control groups for heart rate, blood pressure, or Oucher scores. However, total distress scores were significantly less for the experimental group. These results indicate that immunization is a stressful experience for children. Recommendations include further study incorporating pharmacological and nonpharmacological interventions.