This short-term, prospective study was aimed to assess the effects of partially hydrolyzed formula (PHF) on the prevention of the development of atopic dermatitis in infants at high risk. The infants of parents with allergy symptoms and serum total IgE over 200 kU/L were divided into 3 groups by their feeding patterns: PHF group (n=15), standard formula (SF) group (n=32), and breast milk (BM) group (n=22). No allergenic food was given during the study period of 6 months, and breastfeeding mothers avoided egg ingestion. Their atopic symptoms were monitored every 2 months. The cumulative incidence and prevalence of atopic dermatitis at the age of 6 months were significantly less in the PHF group than in the SF group (47% vs. 78%, p<0.05; 20% vs. 59%, p<0.05). Those rates of the PHF group were also less than those of the BM group, but they were not statistically significant. There was no difference in the onset age and disease severity. These results suggest that early feeding of PHF to infants at high risk has a short-term preventive effect on the development of atopic dermatitis during the first 6 months of life. Long-term preventive effects should be evaluated.