The impact of electronic health record (EHR) immunization clinical alert systems on the delivery of other preventive services remains unknown. We assessed for spillover effects of an EHR immunization alert on delivery of 6 other preventive services, in children 18 to 30 months of age needing immunizations. We conducted a secondary data analysis, with additional primary data collection, of a randomized, historically controlled trial to improve immunization rates with EHR alerts, in an urban, primary care clinic. No significant differences were found in screening for anemia, lead, development, nutrition, and injury prevention counseling in children prompting EHR immunization alerts (n = 129), compared with controls (n = 135). Significant increases in oral health screening in patients prompting EHR alerts (odds ratio = 4.8, 95% CI = 1.8-13.0) were likely due to practice changes over time. An EHR clinical alert system targeting immunizations did not have a spillover effect on the delivery of other preventive services.