OBJECTIVES: The incidence rates of atopic dermatitis (AD) and relative risks (RR) associated to a brand of partially hydrolyzed 100% whey formula manufactured by Nestlé (PHF-W) and to extensively hydrolyzed formulas (EHF-Whey or Casein) were reported for the prevention of AD in infants who are not exclusively breastfed. METHODS: Szajewska et al. had previously undertaken a meta-analysis determining the incidence rates and RRs of PHF-W compared to cow’s milk formula (CMF) and EHF but details were not for provided for PHF-W vs. EHF. This analysis sheds light on the latter comparisons and extends the analyses to 3-month cycles from birth to 36-months of age. Included were any relevant randomized controlled trials comparing the use of PHF-W with CMF or EHF for the prevention of allergies.  The primary outcomes of interest were the incidence, cumulative incidence and period prevalence of any allergic manifestations and AD in particular. Of 84 retrieved citations, 15 studies were included for analysis of which 6 studies pertained to PHF-W vs. EHF.  All efficacy data were converted into inputs for a spreadsheet decision-analytic economic model based on 3-month cycles by applying weights derived from the Szajewska et al. meta-analysis and calculating them at 3-month intervals for input into an economic model. RESULTS: The analysis sample included 557, 559 and 580 patients for PHF-W, EHF-Whey and EHF-Casein, respectively. A RR of 0.75 [0.54,1.05] at 0-12 months and 0.80 [0.63,1.02] at 0-36 months was obtained for  PHF-W vs. EHF-Whey while a RR of 1.06 [0.74,1.53] at 0-12 months and 1.13 [0.87,1.47] at 0-36 months was determined for PHF-W vs. EHF-Casein. All efficacy data were adapted into 3-month indicators. CONCLUSIONS: It appears that the efficacy of PHF-W falls within the range of the other two extensively hydrolyzed formulas.